Vodacom giving out personal information

I'm really unhappy with vodacom giving my personal information to outside companies, I got a call from a lady stating she's from vodacom and had all my info from my I'd number to the 2 contract numbers which was due to upgrade. I had questioned her a few times on the call asking if she really is vodacom direct and she said yes,turns out she's from a company called mondeo mobile, which I might add does not give you what was promised for the upgrade. I requested a copy if the call which they say I must go to a vodacom store only then they can give it to them for me to listen,as I would like to get my lawyers involved and get both contracts cancelled due to the lies told and with vodacom giving my info out without my consent. Being a big company like vodacom they feel they can just do what ever they want