Terrible service from Affinity insurance

I have sold my car and called Affinity to cancel my insurance and they’re saying I need to send an affidavit to say who I sold it to and when. This is short term insurance which I can cancel at any point regardless of the reason and why I should go and queue at a police station in these COVID times is beyond me. My debit order goes off on the 29th and they’re dying it will go through and I’ll only get a refund if I send proof of transaction for selling the car