Fed up with Cell C

I am at my wit's end with Cell C. I took out a cellphone contract with them towards the end of last year. The first month my account was debited with the R200-odd per month cost, for the contract. The following month my account was NOT debited, and this has happened every month since. I then end up being disconnected, charged a penalty for not paying and then have to physically go and EFT the money... EVERY MONTH! I don't even know what my actual contract fee is because of penalty fees (which i should NOT be paying for) keeps on being added to the amount. I end up calling customer service every time, and every time they cannot help me and can't give me a reason for this recurring problem. I have checked and they definitely have the correct bank details. At the end of the day, I look like a bad-payer and my credit record gets negatively affected... when actually, the money is there EVERY month just waiting to be taken. I am really tired of this, and as i write this, i am anticipating my phone to be disconnected (yet again!) any moment... while my bank account patiently waits for the deduction!