Huge overcharge on bill and charged much more than advertised

I signed up for the Telkom UNLIMITEDhome 10Mbps, which includes line rental and free installation and modem for R799 p/month. However, my bill for this month came to a ridiculous amount of R2364.92, even taking away a R700 deposit I had paid and "discount" of R263.16. They also charged service or installation fees of R638.55 on top of the R2364.92!!! The package was clearly advertised for R799 p/month all inclusive including line rental. When we got the bill, suddenly the "extra" line items add up to way more than R799. You can't just charge people ridiculous amounts on their bills and get away with it. I've raised a dispute and the reference number is: ********** 4. Sort it out, I don't want to waste more time on this - I had to waste time for installation and getting everything set up and now I have to waste time to sort out the bill. I should charge Telkom for the time I'm spending on them!