Ongoing Unauthorised Debits by On Air

I fully paid off my decoder from On Air, yet they continue to debit my account. I contacted them via WhatsApp requesting the debits be stopped, but the deductions continue. They claimed to be investigating, but no resolution has been provided. I’ve also requested a refund for the two unauthorized payments. This is unacceptable—I’m now paying for nothing. I’m very disappointed with this company and would not recommend them.