Frustrated client

I am giving up now with Vodacom,to think that I have been their loyal customer for more than 10 years and this is a thanks I get for my loyalty. I have been reporting this account that appears under my ID NO which dont belong to me on numerous occassions,for some strange reasons only known to them it is still there. It doesnt help me to be advised that Experian is not reflecting that account then how do I know what balance this person owes and their account number if its not there?