ACCOUNT PAID UP STILL GETTING LETTERS

On the 12/8/2015 i called into your call center for a settlement amount on my makro account. The person that assisted me gave me an easy pay reference number. Payment was made for the full outstanding amount on the 13/08/2015. In September i was getting calls and messages saying i have not paid my account, when in fact i settled. Only then to find out the person who gave me the easy pay reference number was the WRONG NUMBER!!!!! I sent an email on the 8th September to [Email Removed] with the attached proof of payment but yet im STILL getting threatening phone calls from your (VERY RUDE) call center! On the 13th of September i sent the email again to the same email address because im getting SMS's saying you will hand me over for non payment. And you charge me for every sms you send me and every call you make to me. I will not be pay a CENT more than what i paid on the 13/08/2015!!! IF this account is not closed and i continue getting threatening letters or sms's i WILL be taking this further!!! And YOU will then pay for my legal fees for YOUR STAFF ERROR!!!!