Bad service and harassment sms everyday

I had an account with Telkom which was handed over to Vericred collections I received call and sms from them everyday regarding this account I made the full payment and sent them the proof of payment over a month ago I still receive sms from them everyday with final demands I called in and spoke to lots of different people I was asked to email the proof of payment to the supervisor Deon which I did he confirmed that he received the proof of payment but a month later still nothing has been done aboutbi was told that I would receive a paid up letter in a couple of days but nothing I called in to find out what was happening but no one can seem to give me an answer about it I emailed Deon a couple of times again but no response from him.