After 7 hours on hold, and a very rude chat supervisor, why can't I cancel my service?

I've truly never had a worse customer service experience in my life. I have tried 4 times to cancel my service. Each time I've waited over 2 hours to speak with someone. 3 of those times I had to hang up before getting the chance, because... I have a life and responsibilities. Tonight, I finally got a live person to help me - not on the phone of course - on chat. I'll take it. However, Supervisor Daryl very matter of factly informed me that I needed to call customer service to cancel, RIGHT AFTER he told me I could hang up the phone because he'd be able to help me out. He was fully aware that I was trying to cancel my service. I had already been waiting on hold for 45 minutes! Back to square one. So that's a total of almost 7 hours on hold with 0% progress. I'm ready to "mobilize my world" as far away from ATT as possible. I still need to cancel my service. I am moving at the end of the month. I also would love to be refunded for the last 2 months of service, since that's how long I've been trying to cancel, and that's how long my TV has been broken. I have a feeling that's as likely to happen as a magic genie granting me 3 wishes, so I'll just take cancelling my service when I move. Can you tell I'm mad?