Overpaying dstv account

I am very disappointed in how my matter has been handled by dstv agents. I have been sending them couple of emails and calling regarding my complain till today no one has helped me. I have been overpaying my account because the agent who was supposed to add extra view after upgrading from a dstv compact to explorer didn't do what the installer ask him to do instead I have been paying two accounts since from last year. I have been trying to get help in order to be paid back that amount dstv owes me.