Collections gone wrong

I owed money to a financial institution and was contacted about a year ago by Asili Risk Management, consultant Walter, who confirmed that they are collecting money for the financial institution. In February 2015 I was contacted by Walter again, who confirmed that if I increase my payment to R310.40 then my account will be settled in June 2015, which I agreed to. The same premium for July and August was also paid. I went to the bank in October and reversed the payment for September. When I phoned Asili and spoke to Walter, what a rude person he was, after I told them that I would like them to pay back the money that I paid in July and August. Only to find that they never informed the financial institution about it. What a discrace to work with someone, who thinks that with his tone of voice we just have to listen.