COMPLAINT! LIED TO ABOUT BILL AND CHANGING CELL PHONE PLAN

I live in CA.  AT&T lied to me about a cell phone plan change and I want to file a formal complaint. On 12/28/18, I checked my bill and I saw I had incurred $50+ in minute overage fees. I never received any notification from AT&T that this happened, so I called them and spoke with a rep named Ron. I told Ron that I’ve been a loyal, customer of over 20 years and this was outrageous. I mentioned to him that I’ve only gone over my minutes once in 2015 (when my dad died unexpectedly, and I had to make more calls that month that usual). During that time, AT&T never informed me of this and when I called, they erased the charges, and said I would receive notifications if I was going over my minutes in the future. They also said they’d escalate this issue to their technical team to find out why I never got any notifications of any minute overages and I’d be notified within 48 hours of their findings. They never got back to me with any findings and I just received an email that this case was closed. When I mentioned this to Ron on 12/28/18, he said he was unsure why this happened again. His solution was to switch me into a new $70 unlimited talk, text, and data plan. He said that my upcoming bill would look a bit weird due to the pro-rated fees and changes, but he assured me that I would not have a huge bill (only $70 not including the taxes and fees). Well, I just looked at my upcoming bill, which is due on 1/19/19 and it's $197.08! This is outrageous, so I called AT&T on 1/7/19 and spoke with Joseph (ID#JC307D). Joseph told me he would just give me $50 off my bill and I could break the payments up to make it more manageable. I told him that this was not the agreement when I spoke with Ron in December, and I was assured the bill would be $70 no including taxes and fees. Joseph said he would not honor that agreement. When I asked Joseph why I never received notification that my minutes were over on my plan he wasn’t sure why. I told him I had the same issue back in 2015 and there was an investigation into this, in where I never received the findings. I only was assured it would never happen again. Joseph said he was going to not offer me the $50 off my current bill and escalate this issue to their technical team and I would receive a call with their findings and decision about my bill no later than 1/9/19. I had offered to give Joseph the 2015 technical issue case number but he declined to take this information. Well it’s now 1/11/19 and this issue is still not resolved, I still have a bill that’s almost $200, when I was sold a plan that was supposed to be $70 not including taxes and fees. I am formally filing a complaint with AT&T regarding this matter. I was tricked into changing my long-term grandfathered plan under the guise it would not increase my upcoming bill. Now that didn’t happen. I called them in a timely manner and I was told it would be resolved by 1/9/19, and they would find out why this issue was not resolved when I initially complained about this in 2015. They are not doing this and what they are doing is extremely deceptive, especially to a customer that has been in excellent standing with them for over 20 years.