Ridiculous Service From MTN

MTN service has been nothing but pain in the rear end .Contract ended last year November ,however to this day we have been trying to cancel it with no success .As I am writing this I have a blocked phone because apparently 'It was not paid '. I keep getting data and minutes + sms-however when I load my own to avoid using theirs it depletes theirs first-which I am told thats what we (My partner being the account holder -I use the phone though )charged for .