Mtn
Insane invoice

Mtn

Been with Mtn for 15 years my account in normally 1700 some times more. I travel to bots and other country's for work so I I'm on roaming. For 7 day s in Zim they invoiced me
R64 000. That is absolute insanity. My bank phones me immediately if some unusual transaction go on and ask me security questions to verify if it is me. Not one person phoned me from Mtn to tell me your Internet acc is going sky hi they cut the phone the day I got back. Where can somebody or any body afford that amount for a cell phone acc this is steeling. Please Help!!! What is my next step.