Mtn customer service socks!!!!

I have had the most frustrating experience with Mtn. I received a payment instruction through payat and paid my account up to date. My service has now been suspended and they have not received the oayment. I am an elderly person with disabilities and is not mobile. After 28 emails to customer care, I took a taxi to my nearest store only to be told that all they can do is to log a complaint. My bank statement reflex the payment but they want proof on pdf form that the payment was accepted. How on earth do I do that. Nobody can help me and I can't get hold of an agent.