Settlement letter

I have made a payment since the 18th of February till today am struggling to get the settlement letter, I have been calling in since last week with no help all they aay is that the payment is not reflecting and I should wait 24 hours ,I have been waiting with no help, I don't understand how they can give an option on paythru when even them selves the dont understand , I have done my part and paid you , now please do yours and send me the letter Acc no ***