AT&T upset customer billing

Hello,
I have been overcharged every month and charged for services I did not request. I have called every month and after about 3 hours , I'm told credits will be issued along with a Visa card with credit on it for a 100 for my troubles. This started in June 2016. I have kept all and documents everything. I have filed two dispute cases with any response back. Last month I finally spoke with a girl named Bridget whom I went through every statement with her and provided where over charged and together agreed on a credit due each month. When finalizing the total balance it came to $1600.44. She said she needed to get approval and would be back on the line soon. When she returned to our line connection, she stated that the credit was approved and she was applying it right now and I should see it on the next billing cycle. I waited for the next billing cycle and I was charged the $300 plus for two lines and direct tv. I have two lines and contracted with AT&T u-verse that my month charges would be...
$106.47 for unlimited everything for two lines and $60.00 for direct tv. On the second case filed I spoke with a girl whom seem genuinely concerned. She was able to give me some credit for the direct tv but in the system there was nothing showing I even talked to Bridget resulting in filing a case again and ask to pull the call. So much more I could say. This was on 2-19-2017 and was told it would be resolved no later than ten days. Still have not heard a thing but received phone call stating my bill was past due. After posting my last message I received a letter from AT&T stating that my post violated the guide so so they deleted my message along with them shutting my service .