Vodacom what is going on?

I am SICK of Vodacom. I have always had more than one contract. As they end I WILL cancel each and every one. They do not care about their customers and incorrect invoicing and just deducting what they want. I had a data contract only, no device as it was pd up, which I received a early cancelations quote for and I paid it and emailed everything they requested by the 1st of August only to find they have made a second invoice out to me to be deducted 1st Sep an extra R377 where I was supposed to be paying just over R900 now the R377 is added. This invoice I have no idea what it is for as i didnt receive it, inly a sms with the grand total. 2 vodacom consultants said it is incorrect and I need to be credited as that specific number has been cancelled and I paid what I was quoted. They said they will get back to me today Tuesday 27 Aug. To no avail. I want this sorted. I will stop paying and you can hand me over I don't care. Why must I pay for something I have no idea what it is for and nor does the actual vodacom consultants???