Unhappy Comcast customers are learning: Nothing gets results like recording your frustrated calls with the Internet service provider.

Last month, former Engadget editor Ryan Block recorded an epic phone call with the company in which he tried to cancel his service — but was was unable to shake a Comcast service representative for at least 18 long minutes. Now, there’s the experience of Tim Davis, a YouTube user who says he was able to get a promised refund from Comcast only because he had an audio recording proving he was owed the money.

According to Davis’s account, it all started when he did a simple, self-install of a Comcast cable box when he moved to his new place in Oregon. Everything was fine until about two weeks later when his Internet connection started dropping in and out.

He called Comcast, and the company confirmed there wasn’t anything wrong with his self-install and promised to send a technician for free to fix the outdoor line. Davis recorded the call.

But later, Comcast billed Davis $181.94 in total for services, including the technician checkup, “failed self-install” and a wireless network setup that Davis said didn’t happen at all.

In his first call to Comcast customer service, Davis insisted the charges were bogus because there wasn’t any failed self-install and that the technician didn’t install a coaxial cable jack as the company was claiming. The customer rep then placed Davis on hold for an hour, Davis said. He hung up.

He called again, this time reaching someone described as a Comcast “supervisor.” The supervisor explained that instead of being charged $182, Davis should have been charged $82, including $50 for the failed self-install and $32 for failed video self-install kit. The supervisor offered to give Davis the “BLAST+” Internet service free for 12 months, rather than refunding Davis the $82 charges. Davis said the upgrade only had a retail value of $60 ($5 per month for 12 months), which meant Comcast would still owe him $22.

That’s when Davis told the Comcast supervisor that he had recorded the earlier call where Comcast promised not to charge him.

“Well, I have a call recorded where the agent tells me in no uncertain terms that there will be no charge,” Davis replied. “You cannot bill me for something that I did not authorize. You cannot tell me that it’s free, then bill me anyway and then tell me that you cannot un-bill me or credit me for the bill.”

David then played his recording of the initial call to the representative. The Comcast rep promised to look into the issue and later called back to tell him the $82 would be credited back to Davis’s account.

Davis asked why she didn’t do so during the earlier call.

“We try to negotiate, and again, that is a valid charge. But since I advised my manager that there is a recording and you were misinformed, then she’s the one who can approve that $82,” the Comcast rep explained.

Davis asked to confirm, “You’re telling me that if I didn’t have a recording of that call, you wouldn’t have been able to do it?”

“Yes, that is correct,” says the rep.

And yes, he recorded that part, too.

Here’s the video posted by Tim Davis on YouTube explaining his experience with Comcast (The video contains some salty language.)

“This is not the type of experience we want our customers to have, and we will reach out to Mr. Davis to apologize to him,” Comcast said in a statement referring to Davis’s calls. “Our policy is not to charge for service visits that are related to problems with our equipment or network. We are looking into this to understand what happened and why it happened.”

In a phone interview, Davis told The Washington Post that he recorded his calls with Comcast because this is not the first time he has received poor customer service after questioning suspicious charges on his Comcast account. He said in the past there have been $10 or $20 charges on his account billed as “service charges” that he eventually gave up fighting because they take up too much time to dispute. Another time, Davis said, he was given a new customer promotion for 12 months, but it was then canceled in the sixth month. His bill doubled, and he ended up paying the higher amount until he recently moved.

Davis said he received tons of e-mails and comments after he posted his YouTube video describing his experience with Comcast; the video has more than 180,000 views after being picked up on Reddit and the Consumerist.

Davis’s advice for people in similar situations?  “Record all your calls because you just can’t trust them.”