Free for all at MTN

I received a phone call from MTN (green tick verified by Truecaller) to say that my current data contract had expired and I can choose to upgrade or keep it the same on a month to month package. I opted to upgrade to a Mega L deal for R499 pm. I went in to MTN store at La Lucia mall to make sure everything was ok because I received a suspicious request from MTN to debit me R20000 on the first of every month. The guy in store says yes everything is fine youve been upgraded to a Mega M package but I don't know why you're loaded for a debit order of R499 when that package costs R315 a month and even if you were on a Mega L that package only cost R419 pm. Obviously upset I told him to put me on the mega L I had agreed to and make my debit order R419. His response was we can do that but I'm going to charge you a once off fee of R480. I have never been more confused. How can a MTN lie/****** up result in me paying R480 to fix? He laughed and said I can't help you, we can't change or see what the online guys do. Absolute insanity.