Telkom terrible service

I cancelled our business Telkom account in March 2018, after our data misteriously disappearing, and their technician telling us that our line is connected to another person's line - we were hearing mixed voices on our calls.

I received a confirmation from Telkom that they received our cancellation request on the same day that I sent it.

I received calls late last year, from a lady collecting the outstanding monies. I told her about the cancellation and she said it was not cancelled.

We are now receiving calls from a debt collector, which call I missed. When trying to phone back the number to speak to the person, on the number ********** - you get a message that the number is not available.

How do you sort this out.????