Vodacom is the pits and affecting my credit score

All of a sudden I have a contract with Vodacom that I have never signed up for , apparently it was done online , the phone was delivered in Cape Town. I went to vodacom shop with no help as I was giving a number to call, I called the number held on for over an hour with my airtime. I don't understand how can a big company like this approve contracts with FICA protocols not followed , no contract and no trace of anything