COMCAST, Don't promise something that you can't do!

YES, I'm an existing customer with comcast and we have been in the business for more than 2 years, our bill went from 119 to 250 last month and I talk to some customer retenttion she promises me to return a $100 credit and it's never HAPPEN. Also when I try to call the customer service 5 times asking about remove the tv out of my account and none of them help me???? What kind of service is it??? Never respect customer !!! I need someone talk to me right now!