MRN dont want to cancel my contract

For the past two months now I have been trying to cancel my mtn contract which has ended. Mtn didn’t even notify my that my contract promotion had ended and the fees would be 100 x more.

I am currently out of the country so I cannot call a 6 digit number. I have tried emailing the retentions department but they keep telling me to call in. They don’t even have an international number to call. Please someone help me to cancel thia stupid contract