Ignoring a client completely.

Good day I have cancelled my mix telematics vehicle tracker months ago. In April 2021 their Cancellation department sent me a letter that it is cancelled and they regret loosing me as a customer. But they keep on deducting a premium of R196.22 rand per month. Try to phone nobody picks up a phone. I reversed my debit order, but they keep on sending me invoice to pay and threatening messages that I will be blacklisted. Even received one today and my Wife telling us to pay money into a fnb account within 10 days to avoid further actions.I am so tired of these people. Phoned them before on a weekend then they tell you you must phone a emergency number.