false phone contact

I was called by one of the Vodacom agent about a contact deal, I told the agent that I wasn't interest about it but still went through we it, the next thing am being called at night by the attorneys that my account is in areas I need to pay, I was surprised because I don't have any account with Vodacom,they need to sort this thing out because everytime I call the Vodacom call centre I get a new person and explain the story all over again,now am being called every week about something I don't have and never had. the last I contacted Vodacom I was told the issue was resolved but still the Mbd attorneys still call me about the account.