Mtn is extremely incompetant

Mtn South Africa is absolutely incapable of cancelling contracts once they have expired. After numerous attempts the past month we are still battling to get our contract cancelled, it expired on 16 July 2022.We were told by the Mtn Shop in Meadowdale to phone that day to cancel since that will be the last day. She submitted the request for me I even have ref numbers. We got no correspondence from Mtn at all since then. I have send numerous emails, even went to Mtn in Three rivers. The mtn stores cannot even get hold of the head office. They dont answer the calls. We are getting billed now even for our hand sets which is paid up now. How is this possible to be so incompetant to do a job. We only want our cell phone numbers to be moved over to prepaid it is not rocket science. I am really upset customer why must we keep on paying if it is our choice not to have a contract anymore