Yep, Comcast lost my business when I moved out of state, cancelled my cable service and my mother took the cable box and personally handed it to a human at their brick and mortar location. That was the end of it, so we thought, though I really wish she'd gotten some sort of receipt as proof of returning the box.
That was in October. In February, I was visiting, camping out in my empty house with no furniture, no television, nothing in it. I came back to the house one day to catch a Comcast guy coming from the side of my house. I asked what he was doing there and he said, "Disconnecting service for lack of payment." I told him I'd cancelled my service back in October, and there hadn't been televisions in the house since. He said, "Oh, ok then, don't worry about it." .. so I didn't worry about it. Until 2 years later when I was moving back, into the same house, and was looking to not only reconnect my cable service, but I was going to do their triple-play with phone and internet and would have been paying them something like $120/mo. This is when I'm informed that I owe them $275 and they'll not connect service again until I pay. Turns out this is for the 5 months from October til February, AFTER I'd cancelled service, returned the cable box and moved out of state. Guess I should have "worried about it" after all.
Now that they knew my current contact info (from me trying to sign up for service), they sent collectors after me, threatening that it would be on my credit report and in a gullible moment, I was convinced that I should pay it to prevent the credit report being affected, then get my money back from Comcast. Yep, I paid, now they owe me. Except of course, they don't care about that. I moved back into my house, and frequently received "offers" of $250 or $200 (kept going down) "gift card" (credit for Comcast services), if I were to sign up for their service. Every one of them goes into the trash. That wouldn't be a gift, that's just part of what they owe me, and I'm not paying them one cent more.