Bad Service - No Invoices

I cannot get my invoices from MTN. On the 10th of August, I emailed Steenberg Offices asking how to get them and I was told that the only way I could get invoices was is to call the call Centre 135. "That is the only way" - I was told. This is not cost-effective for me at all - and I don't have the time to call MTN every month when an invoice should be automatically emailed to me. When I queried this I was told to email ***, which I did and copied D in. No response. Since then I have emailed him 4 times with 'delivery and read receipts' so I see my emails have been opened, he does not respond. I have asked him to send his managers details, no response. This cannot be the only way I can get invoices from MTN. Please can someone from MTN respond, otherwise I'll have no choice but to cancel all my subscriptions at MTN. This is the service I get after I told him that there is a big possibility I will slowly transfer all my other numbers from Vodacom to MTN - about 5, but definitely won't be doing it after getting this kind of service and not getting sent invoices. Please can someone with authority call me to discuss this? Thanks, Shelley