MTN charging ******* amounts and not making bill available for viewing

I have a fixed contract with MTN which is always R390.50 per month. Suddenly this month out of the blue MTN deducts R1462.42 via Stop Order. I try to access my account to see what is going on but I cannot get acces. They send a link via email and when I click on it it states I must enter the OTP emailed to me or send to my phone, neither was sent and I cannot see any bill of any kind to find out what I am being charged for! This is completely unacceptable and surely a case to be reported to the National Consumer Council.