Poor Service - Cancelation Process

I want to complain to Cartrack for delivering very poor service in terms of cancelling a contract with them. I have cancelled and received my cancellation letter on 30 March 2022.

I have done my part by following their requirements set out in the "terms and conditions" but it seems that they are not doing their part. Since March they are running a debit order on my account. I have requested and talked to numerous persons within this organization but to NO success.

I request your responsible persons/management to intervene and get this resolved.

Yours sincerely, Dustan