contract upgraded without my knowledge

I am so disappointed and feeling hopeless. 3 weeks ago I reported that my contract was upgraded without my knowledge and never received the devices Vodacom claims were sent to me. The bill went from 129 to 809 and I was told I must not reverse it and wait for investigation but every time I call the consultants are just as confused as ever and it is clear nothing is being done. I handed over all the relevant documents required and emailed twice but still no response.