unhappy customer

I ve never experiance a bad customer service and bad treatment like this before. I took a contract phone with mtn on the 16th of August 2020 with Mtn Musgrave the guy that was assisting me was Bilal. He told me that i wont pay at the end of august I will only pay at the end of september since it was in the middle of thr month already toward month end i received the bill but i thought it for end of september on the 10th of September my phone was blocked i received the email that stated that i m in arreas i call the call centre the and i was told that yes i was supposed to pay at the end of September it was an error on mtn side the call was logged i was given ref numberand it was resolved the agent even apologised . My phone was unblocked and i received an sms that my quiry was resolved. Today 14th September my phone is blocked again. When i call i was told that I must go back to tje store where i took my contract as he dont know whether that what they told me. I told him i logged the call and i was told that the error is on mtn side. Why am i going back to the store. He carried on saying It was the old system on the new system u must pay whether it after 15th or not. I asked him to call a manager he didnt he decided to argue with me after 30 minutes he decided to go and call the manager but he told me that management wont help me..He came back and told me that there was no management arround i found it very strange. I called again after calming myself down coz i was so annoyed the llady told me no it was the old system that skip mid month I have to pay. What kills me is that I was misleaded not once, im in arreas,my phone is blocked, I dont understand why mtn is not informing all the shops and call centre agencies if the decide ro change their system, it such a big company with *********** employees