The worst account decision one can make

Ive had accounts but this account was the worst idea ever. I have been paying for my account for months ,next thing I get calls from a million debt counsellors,4-5times a day early in the morning. I paid R7000 and requested for it to be closed over 2months ago ,they have been claiming that one of the payments was not received,sent proof of payments 6 times but still everytime I get a call from Nimble group and I keep explaining the same story I'm exhausted I just want this account closed please I'm done.