Can't Cancel My Premium

I traded in a vehicle and called them to cancel my insurance as I no longer have the car and got different insurance for the new vehicle. They put me through to the retentions department were I was on hold for 45minutes and I had to drop since no one answered - I assumed they were busy that day, so I tried again the next day whereby I ended up holding for 30minutes. Nobody answer your call in that department and their strategy is to keep you on hold until your airtime finishes. I then sent them an email with my policy details and asked them to cancel my insurance immediately as I no longer have the vehicle, you receive an automated email with a case number, send them numerous follow-up emails to confirm that indeed it was cancelled but no one responds and today on the 1st they debit my account!!! This is ridiculous, the amount is too high for you to reverse on the ABSA banking app so now I have to find time to go into a branch and manually have the debit order reversed!!! It's pathetic!!!