Account paid in full but 8ta still harassing me

My 8ta account has been paid up over 2.5 years back already. The accounts dept confirmed that there was nothing outstanding, yet year on year I get harassed by 8ta or a collections company for outstanding monies. First the monies outstanding was R3000 odd the following year R6000 and now close to R9000. The more I prove to them there is nothing outstanding and the account is long time closed. This time every year they will harass me for monies they claim is still outstanding. I have contacted them and asked for proof etc to be sent through as well as the history of my account years back and todate i am still waiting for such documentation.<br> <br> Is it now time to take this public?