Wrongfully charged and blacklisted

I was offered a contract in 2018 by Vodacom over the phone ,I agree to the contract then when I received the phone it was a wrong phone delivered, I returned the the phone before I could even use it , the deal was canceled.But after some few day Vodacom deducted my money from the bank , I reversed the money and phone them to sort that matter out.I thought the matter has been sorted until about a week ago I was offered another contract over the phone ,I waited for the phone to arrive ,it did not ...so I went to Vodacom branch and i was told that contract was declined because i owe Vodacom R240 and it was even taken to legal.