Vodacom - *****ing from customers

I highly recommend anyone who is contemplating joining Vodacom to rethink it.

Vodacom has felt it necessary to add 3 months extra onto my 24 month contract which came to an end in December. I was advised by both their in store staff, as well as their online support that I need not worry about anything as my last payment for that contract was indeed in December. ( I have the physical document as proof, as well as a screen shot of the chat) Not only did they charge me more than the last payment but they have now sent me an invoice for my new contract but have also included the old one. The one that is paid up. Now please explain to me how this is deemed professional or even ethical? to blatantly ***** from clients and think that we must just accept it. I have emailed them, with no response, I have posted on their Facebook, with no response, and I have in boxed, with no response. Hopefully this will get a response out of them as my next move is to lodge an official complaint against them with the CGSO as I refuse to be *****ed over by another "big" company who thinks they can get away with everything