PLEASE CLEAR MY NAME ON VODACOM AS I DONT OWE THEM

An agent called me on the first week of Jan offering me a contract (2 J1 Samsung hand set) for R220 a month. They then delivered vodacom turbo handset which was not what i have been looking for. I returned the phone within 5 working day as it was mentioned that if i do so they will take them back with no charge. Vodacom have been bililng me since and i have even reversed the payment through my bank. After numerous calls i still battle to get this cleared. I am in a process of purchasing a car but i cant because this shows negative on my credit scoring ... I HAVE BEEN CALLING VODACOM FOR ABOUT A MONTH NOW AND THEY ALWAYS PROMISE TO REVERSE THE TRANSACTION AND CLEAR ME TO NO SUCCESS

CAN SOMEONE PLEASE HELP ME IM DESPIRATE THE LAST REF NUMBER I GOT WAS 1- ********** ********** AND MY NUMBER IS ********** I AM BEGGING PLEASE CAN SOMEONE SORT THIS OUT. I NEED A LETTER THAT SAYS I DO NOT OWE VODACOM

THANK YOU