3 years and card STILL not cancelled!

I paid my card off in 2012 and received a letter from Discovery stating that the account was paid and closed. In 2013 I was still receiving sms's stating that I owed money, phoned numerous times and eventually card was cancelled, again. Same thing in 2014, phoned and eventually came on to Hello Peter to complain and the issue was eventually resolved.<br> <br> Now, after almost a year of no Discovery sms's, I receive ANOTHER one stating that I owe R50... Really Discovery? The worst part is that my credit rating is being affected by a companies incompetence with no repercussions to yourselves?