Complaint - billed and then blocked

Dear Sir<br> <br> I took out an account with MTN last year, and put a limit on it.<br> Last year December (I think) they decided i needed more sms's although I don't use them, and billed me extra for them.<br> Because the extra takes it over the limit, my account gets blocked. <br> I have called the call centre numerous times to get my account unblocked. The operators unblock me always say that they will speak to the manager about sorting out the billing. <br> I have been put under serious inconvenience by having my calls blocked and am very unimpressed with the service.<br> I have also not received any account statement, although i have asked, except one that was SMSed to me. Seriously? SMS an account to me? it is almost impossible to read.<br> Regards<br> Richard