Who I have the same questioned this topic

We traded in a phone and purchased a new one in April. The terms of the sale included a monthly credit for the following 3 years. In June, we were notified that the credit was in error, and we were billed for the amount of the credit we had received up to that point and the monthly credit was removed from future bills. I have been talking to customer service since June and there has been no resolution. I went to the store where we purchased the phone and after a month, still no resolution. The terms of the sale were final and Verizon can't just change their mind after the fact. Each time you call customer service you get a different person and they have to start from the beginning to try and figure out what has happened. How can I get one person who will be responsible for this resolution?