Bad bad service the worse ever

I had a phone contract with Vodacom, finished paying the phone, I was told I have a month to month for data which I requested to close. I was up and down at Clearwater mall Vodacom trying to close the contract , I was told I owe them 685,85 for data I have never used,I paid it and requested to close the contract. I called Vodacom for the 10th time requesting to close this contact the guy on the phone told me it’s closed,and sold me another product of R79 if I’m not mistaken but I never received the SIM card or anything. Few months later I try to apply for a car and I’m told Vodacom blacklisted me.can Vodacom listen to their recordings becouse that contract was closed. I need my name cleared.