Cancellation nightmare!

I concluded an agreement telephonically and via email with Auto & General for insurance on my vehicle. When I decided to cancel the policy, I contacted the same sales person via email and advised him of my notice to cancel the policy effective 24.09.2022. Today, my bank informed me that R1643 had been debited from my account for insurance from Auto & General. When I called the same sales agent, i was informed that my email had not been received by him(but he received my email today when asking him to call me back) and the cancellation was not actioned. I was then further informed that Auto & General cannot cancel a policy if done so via email. Huh? A telephonic cancellation is preferred over written correspondence? Sorry, what? In this day and age? Auto & General, I'm sure you understand that hardly anyone these days has R1643 to throw away. Kindly refund my money as soon as possible please.