Discount Dispute and Paid up Letter Request

My Capitec loan was handed over to Symington, and i made an aggreement with them to Pay my loan over 3 months where i was given a discount for doing so, I Paid the Loan up over 3 months as per the aggrement, and on the 20th of July 2019 after recieved my Last payment Symington Attorneys promised me a Paid Up Letter within 21 days,

i have spoken to over 10 people, some promising the same thing and some Dropping the call on me. i have been forced to some here because now they are telling me i owe them R855 which was the Discount they gave me, and i have a Discount Letter they emailed to me in May 2019. i need this company to Send me a paid up letter and to update Credit breue as well. because when i went to Capitec Bank, they confirmed that my Loan was paid up and now Closed.