Unauthorized debit order on my account after canceling my insurance

I have changed my insurance from Outsurance to another insurance company 2 months ago. I canceled it in advance with no issues when I sold my vehicle. The agent did ask what my new vehicle would be and gave him an idea what I might buy and he gave a quote. I did not accept the quote but it was at least an estimate once I know what my new vehicle would be and what quotes I can get. Out of the blue, a debit order was done on my account this month without giving any permission for this debit order or ever accepting their quote. And now it is a hassle to get my money back.