MTN - Unable to send invoice but still charge you

I have not been sent my invoice for June 2020. Sent an enquiry, then decided to call. What a mission to get a human on the phone. She asked for my PIN, which suddenly is incorrect, but she cant fix it. The system has been upgraded, I can not download my invoice from their site, and I have not received an email this month. She basically did everything I did. When I asked "Why should I stay with MTN?" She said nothing. When I asked fro a manager she said she'd email me. She has promised that Nelisha will be calling me today. Is it not ******* to charge someone without sending them their invoice????? You take my money but you want tell me what you charged me for. The system is being upgraded so I will receive an sms at some point to reset my PIN. How long does it take to do the upgrade, and why should the upgrade prevent you from sending me an invoice. I want to now cancel my Debit Order, the answer "Go to a store" and I know from previous experience the store will say "Call the call center". You basically go around in a circle. My contract is up for renewal in a few months, tell me why I should stay!!!!!!