The caller's voice, that of a man I know, was tense. Brusquely, he related a story about a bizarre airport incident his foreign house guests had undergone and ended his report by saying, "This kind of thing just shouldn't happen."

"This kind of thing" -- the story related by the visitors, Bernhard Reck and his wife Agnes Rupiya of Swaziland -- began when they arrived in Washington with their baby on Oct. 2. They were refused entry at Dulles International Airport, and they had to fly back across the Atlantic. They arrived for the second time 16 days later. After hearing their story, I was nearly as angry as my caller and decided to investigate.

According to Reck, 23, a West German citizen who has lived in Swaziland for the past decade, when he arrived at Dulles with his African wife, their passports were taken and they were told to wait in the immigration office. After 15 minutes, an agent returned and asked him the purpose of their visit.

Responding that he'd come for three to 12 months to oversee Swaziland Tapestries Ltd. in Stuart, Va., where 12 Swazi women are weaving tapestries, Reck said he was accused of lying and of trying to seek asylum in the United States.

Reck said he protested that he had no such intention and his answers were truthful. Next asked if he knew the meaning of perjury, he was warned that lies carried a $5,000 penalty and five years in prison. Swearing with raised hand to tell the truth, he repeated the answers. "Before I could finish, they told me I was lying," Reck said.

Next he said he showed them the letter confirming his status with the company and a newspaper article about the tapestries woven from Swaziland mohair. He said he was then told he had the wrong visa.

Could he call the U.S. Embassy in Swaziland that had given it to him under a special arrangement? He said he was told his choices were to sign a paper stating that he agreed to return home or go to jail for at least a week, at which time he would get a judicial hearing in which he was certain to be found guilty of violating immigration rules.

"Do my wife and kid have to go to jail?" Reck said he asked. He said he was told they also would be jailed. Reck said he was denied a telephone call or legal representation.

By then, Rupiya, 20, was weeping uncontrollably. "Their tone had been unfriendly from the start," Reck said, "but now they were really upset and told me to make up my mind, that my wife was only crying because the truth was coming out."

Reluctantly, "because I didn't want my wife and kid in jail," Reck signed the paper. Hastily, their return tickets were transferred to another airline, and he and his family were escorted to a Europe-bound plane that had been held 1 1/2 hours for them. Their visas were canceled.

"We were quite upset all the way back to Frankfurt," said Reck. "I knew we had the right visas, but they refused to listen; it was like they had made up their mind." Agnes Rupiya was "pretty upset about Americans in general" because of the experience.

From Frankfurt, Reck called the U.S. Embassy in Swaziland, which determined that Washington "had made a mistake" and the couple indeed had the right visas. New visas, identical to the old ones, were then issued in Frankfurt. This week they warily landed in America again and were whisked through immigration without a problem.

According to a spokesman for the Immigration and Naturalization Service here, the inspector who turned Reck and Rupiya away was in another city for further training and was not immediately available. But he said their records indicated that Reck lacked a proper visa. "If there was a special arrangement, the State Department had to tell us. But we had no such record." Although Reck, who attended high school in neighboring South Africa, was involved in antiapartheid demonstrations as a student several years ago, the INS spokesman said he definitely was not on the State Department "lookout list."

But for Reck and Rupiya, the "mistake" was costly. They had to buy return tickets to America and pay for 16 days of living in Frankfurt -- about $3,000.

Although immigration officials at Dulles generally are considered sophisticated and able in enforcing regulations, there is no excuse for harassing visitors or for officials not to telephone embassy or State Department officials before sending foreign visitors back home. Moreover, making them pick up the tab for an INS mistake is rubbing salt in their wounds.