At its grand opening on Saturday, the tidy new red-brick 7-Eleven Store at 20th Street and Rhode Island Avenue NE was serving up free Slurpees and 29-cent hot dogs, but many neighborhood residents refused to partake.

Giant amplifiers in the storefront parking lot blared pop music that attracted several hundred passers-by and generated record sales for the two-week-old franchise, according to the owner.

But a block away, a group of neighbors watched with irritation from Altha Elliot's front porch steps. The store is a neighborhood disturbance, the disapproving neighbors said, and they plan to continue fighting its presence.

For 18 months, a coalition of Woodridge area church and civic leaders led by Elliot have tried to stop the Southland Corp., parent company of 7-Eleven, from locating on the major commercial strip adjacent to their community of 40-year-old homes and tree-lined streets.

Having failed, they now say they will resist with the only effective power available to them: their pursestrings. Both the residents and Southland have vowed to propagandize youngsters, who are high volume spenders in convenience stores.

"They Southland may think it's all over now that they are here," said Elliot, who is an ANC commissioner and junior high school teacher in the area. "What they don't understand is that our anger has only begun."

Coalition members charge that the store will change the quiet residential character of their neighborhood and increase litter, crime, noise, and traffic at an intersection that is close to several schools and a church. Their position is supported, they say, by at least 1,600 area residents who signed a petition protesting construction of the store. They presented the petition to Southland more than a year ago.

Their plan is to rally those and others to deny the corner store the community dollars that Southland representatives acknowledge are 7-Eleven's lifeline.

"We certainly would never locate in an area where we didn't think there was a need," said Mike Greiner, Southland's regional manager.

The Dallas-based Southland is the largest franchiser of convenience stores in the country. Company officials said they saw the Woodridge location as "a middle-class neighborhood of individual homes that was fairly stable, that had the additional benefit of the traffic up and down Rhode Island Avenue and that was not oversaturated with food stores." A Safeway closed in the area several years ago.

Southland was aware of the community's concerns and said it believed it had addressed them before construction, said Ron Fountain, Washington district manager for Southland. Fountain said in his 11 years with the company he has encountered occasional resistance of this type in other cities, "but this is probably the most aggravated I've seen."

City Council member William Spaulding (D-Ward 5) said the resistance stems in part from increases in loitering and crime that residents have observed at other new 7-Elevens around the city.

Coalition spokesmen said Spaulding is one of several political leaders who had promised to help them stop the store's construction, but did not. "I understand their concerns and I share them," Spaulding said. "What I told them was that I would do everything I could, but the fact is I checked the laws and . . . what they were doing they had a right to do."

Some of the community's resentment, Elliot said, is related to what she called Southland's track record of coming into black neighborhoods and pushing out existing mom and pop businesses that were run by local residents. The 7-Elevens often are franchises owned by immigrants who hire their own family and friends.

"What we resent is their pretense of fulfilling a need in the community, when what they do is take business and money out of the community and literally rape the surrounding neighborhood in the process," said Elliot.

Southland spokesmen acknowledged that most of its 29 stores in the District are owned by immigrants, most of them Asian, and only six by blacks.

Fountain said the company has been actively seeking local black franchise purchasers. When it had no response to an appeal in the Woodridge area, he said, it selected Hafke Kitessa, an immigrant from Ethiopia with a bachelor's degree in economics and a master's in African studies from Howard University.

Kitessa said he had to work several odd jobs over the last 11 years, from waiting tables to driving a bus, while his wife worked as a bank clerk, to save $30,000 to buy the franchise.

"We are addressing the community's concerns," said Fountain. "He Kitessa has already hired two employes from the community."

"My main concern is the traffic and I just say we don't need it," said Enez Martin, a coalition leader and ANC commissioner. "Everything in there just costs more," she added.

"We are committed and the more we talk to other people, the more we find who feel the same way we do, . . . . it's all a matter of education," said Elliot.

Both coalition leaders and Southland said the key to who wins in the conflict may lie with the community's youth, the high-volume consumers of Slurpees and Big Gulps, two 7-Eleven drinks.

Elliot and other residents said they plan to try to persuade youngsters not to patronize the store with the help of teachers and parents. Kitessa said he, too, plans to visit all the local schools, with his Southland field representative, and hand out free slurpee coupons left over from the grand opening.

"I'll never forget what they told us at one meeting," said Elliot. "They said, 'we encounter people like you all the time and then we go in and six months later those same people are shopping in our store.'

"Well we're not going to do it . . . . We're not going to walk around with signs, either," Elliot vowed. "We're going to be nice and quiet, like dripping water . . . . You know, it can eat away at a porcelain sink. It's a nuisance, but it does damage, too."