Remember "free trials" do continue unless you cancel them directly. This means that as you previously had a Free Trial to Apple Arcade, regardless of whether you used it or not, you would continue to be charged unless you directly cancel the subscription.
You can view and cancel your subscription following the steps at How to cancel a subscription from Apple – Apple Support
You could potentially try and claim a refund by contacting Apple's Form > Request a refund for apps or content that you bought from Apple – Apple Support however this isn't guaranteed and it is up to whether Apple allow the refund or not. Apple generally has a 90 day period of refunds, so you could try and get refunded for most of these charges.