Home choice settlement letter

Good day. I am writing regarding my homechoice account which was handed over to MBD. I got a call from a consultant who gave me a discount to settle my account. I paid up the amount immediately. Home choice has been calling non-stop harassing me everyday requesting me to pay the outstanding amount which I know nothing about. I have tried contacting MBD for the past two weeks requesting for my settlement letter with no success. The call center agents are so rude and lack respect for clients. I don't understand what's so difficult for them to write a simple paid up letter and communicate with Home Choice that I have settled my account.

This is the worst, terrible service I have ever received in my whole entire life.