over charged bills

I have a 2 year contract with altech auto page for R250 and received a laptop and ****le with it. In june last year I received a bill of over R2000 and it came off my account, I couldn't understand why this bill was so much as I hardly use my laptop to browse the web. The main reason is that there is never any network coverage in my area and always waste my time trying to get connected! Last month I received a statement of R650 again! And still I can't figure out how io can be receiving these random high bills as every other month my bill comes to R271(from R250) because they don't tell you there's additional charges before u take the contract. Being robed of a R21 every month just wasn't enough I guess. I am soo angry with this company I will never take out another contract with them! I want my money back because I know this **** don't work!