Cancelling service doesn't cancel service

Hello,

I had been having issues with my service for a very long time. Comcast couldn't fix the problems, and in a last ditch effort to try and fix them, we were going to up the speed to 1gig. They were scheduled to come out on a Wednesday. I cleared my schedule, but they didn't show up. Thursday I told them to come out by Friday at 5:00 or I was cancelling everything. They did not show up by 5:00 that Friday, so I cancelled (I called to cancel the install, I emailed to cancel the install, and I sent messages to the twitter support to cancel the install). They showed up Saturday anyways. I finally spoke to someone a few days later who assured me that I wouldn't be paying for the previous and forthcoming bills because of the service not working (I have the emails about credits being applied), and that by signing a disconnect form, it would ensure that my remaining balance was $0.  I did this and returned my equipment.

Today I received a bill in the mail for service AFTER I signed the disconnect form and AFTER I returned the equipment. I've emailed and twitter DM'd contacts up at comcast, but no one is responding. I need this removed immediately and I need written proof that the account is closed and that the balance is $0.  I have all of the receipts.