Vodacom ripping u off

After my mom in law passed away i contact vodacom to tansfere her contracts over to my name. I was sent forms and told to go to a vodacom shop to complete the tranfer. I sat at vodacom for 3 hrs, as there was only 1 person who could help me. I went in with my forms, an was told it was the wrong forms. He printed the correct form and i was told to fill in my details and sign. Now, im being billed 150 per transfer which i was not advised i will be billed for. I contacted customer care who conected me to the store. The store is refusing ro remove that charges, saying i signed for it. I was never informed what im signing. And will not be paying this!