Debit order cancelation

I have cancelled my contract with blue label connect on the 11th June 2024 and the device was collected on the 14th June 2024, they notified me with once off debit order of R449.00 of which we agreed on and it was debited. But now I'm still debited every month, it's been 3 months now and I've been calling them to cancel the debit order and refund but they don't keep their promises. I would like hellopeter to help me to cancel the debit order and get my refund