How do i speak to someone who can adjust my final bill?

I need to have a conversation with someone who has authority to adjust a final bill more than $30.

This is what happened:

April 16 i was scheduled to have DirectTV and internet installed for $45/month. The install tech said he could not do DirectTV because there were line of sight issue. He said I could offer me the same deal on Uverse. I agreed.

April 19 i noticed i would be billed $142/month for the service. I chatted online and explained that i was offered 45/month. the rep said it would be taken care of and i would get a confirmation call. No call was ever received

May 1 it was still not corrected so i chatted again. This rep confirmed that it was in my notes i was offered $45/month. He said it would be escalated to his supervisor and assured me i would get the rate i was promised.

May 19, still not corrected. i chatted and was transferred and told to call in. I called in and was transferred many times, finally reaching someone who said I could not get the $45 rate. So i cancelled my service because i was mislead about the rate. The rep said he understood the situation and it would be taken care of and reflected in my final bill.

Mid June rolls around and I get my final bill which gives me the credit from May 19-June 19 when i did not have service, but charges me the full rate pf $208 for April 16-May 19 when i did have service. I dispute this amount. I have tried several chats in the last week and been told i would receive phone calls, but never did. Today i chatted and length with a rep who then transferred me to his supervisor, and the chat was promptly dropped.

HOW DO I TALK TO SOMEBODY TO RESOLVE THIS ISSUE?!?!? What I initially thought was a simple misunderstanding is now seeming more like a blatant bait and switch tactic to get me to switch to Uverse, followed by incorrect information to keep my signed up for a month, followed by avoidance to resolve the issue.