Loyalty Department Pricing Not reflecting in bill

I was going to cancel service and the loyalty department promised me a specific price for Fiber Internet. This was two months ago, every month I have to call spending at least 1 hour on the phone to get a price adjustment for the promised price. 

How do I get ATT to fix this so my bill is consistent and I do not have to call every month for an adjustment. Is there a number to call (other than 800.288.2020) to speak to someone.