Closed account but continue to be billed

I contacted the MTN help line in mid September to close my account. My contract expired on the the 21st July but continued to use the phone up until the end of August. <br> The consultant was friendly and confirmed that my expired contract would be closed and an email sent to me to confirm.<br> I did not receive an email and continued to be billed for a service i do not use.<br> I contacted the help centre via email , received a reply with a question why do you want to cancel or close your account. I also received an incident number. <br> I noticed again that i continued to be charged for a service i don't use. i phoned again was promised action , i also insisted on a refund and wanted confirmation by mail. I have received nothing and continue to be billed.<br> My latest bill is R800 plus for a phone that has been switched off for more than a month<br> <br> Sort this out MTN!!!