Terrible Service

I have been an MTN client since the day I bought my very 1st phone in 2017 and I was quite happy with the service up until now. I did an upgrade this year. The upgrade I did online and not in a store like I normally use to, due to COVID-19. The phones arrived immediately and I was advised when I called in to confirm how far my upgrade application is that a consultant will contact me to confirm the devices before delivery, WHICH NEVER HAPPEND. To my disgust this month my account is sky high but whenever I query my account at the MTN Store in the WOODLANDS MALL I am told to pay my instalment, thinking my account is up to date. Today I spoke to Merglin Pillay that tried to assist me with no luck and handed the phone over to his Manager. His name starts with a K. I asked them why they are not able to give me the correct amounts (THE FULL BALANCE) to avoid situations where my account is in arrears, I was told that they have 2 systems: One system shows the instalment amount that should be paid and the other system that shows a client's full balance (To me this should be one damn system) and the Manager of Woodlands Mall further tells me that I don't understand and I should make my way down to the Mall for him to show me the systems. As a client I don't care about your systems that's not my problem, you are supposed to assist me correctly or UPDATE YOUR SYSTEM to avoid giving us incorrect amounts. My frustration is that they cannot calmly apologize that MTN as a whole made a mistake and direct me but rather shout with me telling me to come and look at the systems. YOUR CUSTOMER SERVICE IS TERRIBLE. After this upgrade I am done with MTN