"Discovery Insure" service failure when trying to cancel my policy.

I recently sold my wife motor car. On the day that I sold it I called Discovery to cancel the insurance as we no longer own the motor. I was pushed around a number of times until i got to the "so called" correct agent. He said he had completed the process to cancel the policy. I then asked for an e-mail with proof and asked him to make sure that a debit order does not come off my account. As that can make things complicated. He said that they were currently having system problem and I should get the e-mail later in the day. Under normal conditions I would wait on the call until I get the proof. However due to the Covid situation I am stuck out of the country and was on a roaming call. The cost of this single call has costed me R300 for 30mins and unfortunately to-date i have still not received the cancellation e-mail. Before getting hold of discovery via a call I also sent an e-mail to discovery asking them to cancel the policy.

Today I logged onto my internet banking and see that discovery have debited my account. Why !