Very frustrating experience

Very frustrating experience. My Diners Club card was paid up and closed a long time ago but in July this year, this account appeared out of nowhere on my credit report with a balance owed of R8,804 in 150+ days in arrears and this month increased to R8,957. I was referred to call a Henriette Putter at Standard Bank on ********** to resolve this and told that only she can sort this out. I have tried to call her a number of times almost every day for the past two months on this number but the number is constantly "Line Busy". All anyone can tell me is that the card was cancelled in July this year. I have not used or even had a card for over five years!