Vodacom ********!!!

I'm disgusted with the service I received from vodacom. A month ago someone took out TWO cellphones on my name, I was never called or consulted regarding this matter, I only found out yesterday when I realized I was being billed more than what I usually pay. I don't understand how such ***** takes place under my name without them contacting me, now I have to pay money that I know nothing about. I refuse to pay that money and I'm going to fight vodacom until they rectify their mistake. What documents were produced under my name for them to process such? This person took out these phones miles away from where I stay and I'm being told to go there. I'm really disappointed in their service.