Horrible Service

The collection company that you guys gave my account to are *******, I had an agreement with them to make a full payment on my account. The agreement was R 5 123 to be paid on the 2nd of October, I could not make the payment at the time on Tuesday (16 Oct) I then recieved an sms to say I must urgently make the payment,On the 17th I made the payment and sent the proof of payment. Today they call me telling me I need to pay R1500 more because the discount fell-off. The latest communication with them was that R 5 123 is the money I need to pay to close the account and thats what I did.