Worst service and unprofessional call centre staff

I took out a service plan which I cancelled the next day. I received an email to confirm the cancellation. A few days later I checked my installment amount on the app and it had increased, I called them and I was advised it will take 14 days to update, 14 days had passed, I called again and I was told it will be escalated. I called again 2 days before my debit order went off and I was told they will make sure the correct amount will go off my account but that was not the case. I called again on Monday 27 September and they gave me a turnaround time of 48 hours for feedback, no feedback has been received. I called AGAIN this morning, the lady I spoke to left me on hold for 30 minutes and she came back to me and said "a manager will call you back right now" and I'm still waiting for the call.