Account still debited 5 months after cancellation of services

I ran out of patience with Telkom. My account was cancelled as from 1st December 2019. I was no longer under contractual obligation with Telkom since my contract expired after 2 years and we paid on a month to month basis. They however kept debiting my account ever since. Telkom now owe me R1751.80. Since I am no longer living in South Africa I emailed Telkom several times and received no assistance!