Cut off by MTN in spite of payment in time

I am a customer of MTN for close to 30 years. I pay monthly for the largest package available on average R 2500 per month. By mistake I did not make a payment on month end as normal. MTN send me a reminder SMS on 13 Nov at 11h43 to make payment or be suspended in 2 days. When I tried to make a payment directly after receiving the message, I received an error message that the reference was incorrect. On 14 Nov at around 06h00 my outgoing calls were suspended (18h after the reminder). I made the payment and went in to a branch. The branch was locked due to a stock count. When knocking on the glass. I was waved away. I tried to open the door and was stormed by 3 personnel and shouted at. I left and tried to sort it out by dailing first customer care ad after holding for half an hour I dailed 808 which inform that they unable to attend to a query with the following message. Please note that our services has been disrupted and the Call Centre has been closed. Use self help options, which require a password which I don't have. MTN YOU ARE THE WORST, The previous time you charged me for data I did not used, my wife's phone was cut off and after months it was not resolved and I paid just to get the service reinstated.