DISGUSTING DISRESPECTFULL STAFF

So a receive my statement today showing me that i am in arrears with over R513.46?????? Good golly you guys really know how to **** of your clients. This is unfortunately not my problem and i am now going to stop all debit orders to Atlech at my bank untill this is sorted and i will NOT pay this amount nor the amount that you debited last month as Zaheer clearly said that my monthly installment will be R200 and i see now it is now R268.18? Please revert back to me asap!!! I would like to cancel this contract ASAP and i will not be laiable for any cancellation fees as i have no really had enough with your service and all the issues i have had for over 2 years of being with you all. From 3 faulty phones in one year to being debited wrongly, i am now fed up.