Settlement letter

I am waiting on a settlement letter the accounts pay up to date for a old account taken in 2014. I don't know why its taking so long but I have been in communication with many telkom consultants an they have all confirmed payment received my accounts actually in a credit, I was told to make contact with a third party collections but they don't have records of my profile or accounts for a company that's supposed to be big on customer service why am I the one having to do the follow ups no one that's help me made a effort to call back. If the customers always right why am I getting such bad service! Every person I have spoken to so far they see the payments but and we will send a settlement letter shortly still nothing.