How hard is it to get a Paid Up LETTER

My name is Lutendo Laka, my id number is *** I had a loan with Wonga then I lost my job. On the 17th September I got an SMS that my account was handed over to Anthony Richards and Associates, I took my phone and called them then on the 19th September I made full payment amount of R4063 I called them the following day and they said they will send me the paid up letter but I never received it I called them Saturday the 21st and they said I will get it Monday. Come Monday there was nothing on my email. I called again today the 25th and they said they have sent everything to Wonga they are still waiting for Wonga to send them the paid up letter as it comes from them. I contacted Wonga online chat and the person I was chatting to said they can't issue the paid up letter until Anthony Richards and Associates send them proof of payment which I made. Now I don't even know which statement to take, how hard is it to get a paid up letter?