Shocking service - Mtn over bills yet again!!!

My wife and I took out 4 contacts at Mtn The Grove, 2 cellphones, 1 Wifi router and 1 3G. Since the first day we have had trouble with our billing and we have been over charged. I can not share all the details here as there would not be enough space. We have requested a limit to be put on our Wifi router and previously we were charged a ridiculous amount as this had not been done. We then complained and we were promised that the limit had been set and that it would never happen again. We were never refunded the extra charge, our account was simply credited even though we explained we did not have the funds available for that to be acceptable as we only provide for what it should cost. Guess what, This month I get a bill for R2900 for the wifi router alone! I am in hospital and have been in hospital for 8 weeks, my wife is alone at home and does not download anything. My first question, how can we be charged this amount considering we have not downloaded anything and secondly, WHERE IS MY LIMIT?!?!?!?! I am fed up with Mtn, I can not afford to pay this amount and I need it to be sorted out BEFORE the debit order comes off my account!