MTN terrible service

Thanks to mtn i was flagged as an "bad payer", after they never informed me in any way that my installments changed from debit orders to having to pay by myself. i asked Vredendal Mtn may times why i do not receive monthly statements and they just told me head office will send it to me. they also never switched off my network as they do when someone is behind on payments. after all of this i eventually paid the amount even though none of this was my fault. I send my proof of payment to various departments of Mtn none of them responds all i need is an paid up letter to clear my name. When i call mtn services they put me through to about 4 different departments and the last person will switch the phone off in my ear. I am so fed up with Mtn they are so useless they are not even able to send a simple paid up letter