Netstar continues to debit my account after I cancelled the contract!

Netstar keeps debiting my account after I paid off the device and called in to cancel the contract. 20 Oct - I paid off the outstanding R657.87 1 Dec - They debited R109 which which returned unpaid and my bank charged me R110 for unpaid debit order. I immediately called Netstar who said I didn’t inform I was cancelling and so I did so telephonically and they confirmed my contract was cancelled 07 Dec - I received a statement which I responded to via email saying I had cancelled the contract and asked for confirmation that the contract was indeed cancelled 15 Dec - Netstar debited my account R109 which again was unpaid and my bank charged me R110.

Netstar must pay me back my R220 and cancel that contract. I will never use them again!