Incorect Charges

I app**** for 4 meg ADSL line with Telkom on a 24 month contract, after my 1st month i decided the line was to slow. I phoned telkom and they informed me that i can upgrade my line at any stage, at this point i asked them to please upgrade me to a 10meg line. This included a free TV100 Media Box. When i received my bill for November, it was R5312.23 where my bill should only have been R982.75. I phone Telkom immediately the next morning to log a dispute as I do not have an extra 4300 in my monthly budget to just pay to Telkom for nothing. They informed me that the dispute will take 14 working days, this is fine as my bill is only due on the 4th of December. the told me the credits will only be granted on my next invoice and that i now need to pay the full R5312.23 or they will disconnect my line in December!!! I agreed to pay the R982.75, but they informed me the line will still be disconnected as it will be in arrears, How can i be in arrears for fictitious charges they wrongfully placed on my account? This is my second moth with Telkom so we are not off to a good start... I enjoy my internet and don't mind paying for the service but i cant afford to pay R4300 more for their mistake, and now i will have to sit without internet until the next billing period when they can credit my account. this is absurd!!!