Incorrect Billing Issue

Hi There<br> <br> Took out a new contract at Canal Walk first one ever, I have them set up my limit to R0.00 so all I have to pay monthly is my subscription and further I may top it myself with airtime and data. However after 2-3 weeks pop by Mtn to check what is going to be debited and to my surprise they advise me on R2500.00 I have them print out my billing to review it as this is impossible and they cannot explain it to me they advise it is wrong though, they stop the payment that goes off anyway and escalate to their billing dept which to date has not contacted me, .... its been 2months and my mobile is offline and they have not responded to me at all and instore they cannot assist !!!. Instore they confirmed again that the limit has been set and that this billing is incorrect but they cannot correct at store level and billing dept at Head Office doesn't get back to me or them. <br> <br> Please assist as I need this resolved ASAP<br> contact me via [Email Removed]<br>