Invoice is R200 mpre than last month

I have been paying my Vodacom account every month, I have a contract, and for this month there is a new amount on my bill that I don't get answers for. I have called 082 135, and just get referred to the Tobi assistant who doesn't answer my question. I went into Vodacom and asked but they are unable to access my account. They told me to call ***, and there I was put on a call with the Tobi assistant, who again wanted to send me my invoice. How hard is it to speak to a person?? I just want to know why there is an additional R200 on my invoice this month? I don't want to have my invoice sent to me, I have it. I can see the amount. Why did my invoice go from R448 to R648 when Im paying a fixed amount every month and I am not in arrears? Tobi is useless for this purpose, I want to speak to a person. Stop putting me through to the assistant like I haven't already tried.