No answer from escalation department

I returned my U-verse equipment and canceled that part of my service. Billing told me I was late in returning the equipment so I would not get the refund. I was not aware of that, so I asked to talk to someone else… They said they would pass the information to escalation department. I have repeated this process three times now , I have an escalation account number, but no one ever calls me about it. I would like to talk to someone who cares. If they do not want to give me back my deposit of $300, I guess they could apply it toward my monthly account since they now have my deposit as well as the returned equipment. I have been with Michigan Bell / AT&T since 1963 continuously except for one year, and feel I should be treated better than this.