Mtn services is poor!

My data contract at Mtn ended months ago and this *********** service is still billing me. I am trying to cancel my contract via the phone (apparently this is the only way I can do it) since the *********** staff at the store cannot help me. The cancelation department is just not answering I've been on the line this entire week for hours and still nobody answers. Mtn service is POOR!

I already got a ref number yet still no help, I emailed them but got an automatic reply.

What do I do?

Mtn service is the worse!!!