If you read the terms of sale you would find that unless you cancel a trial subscription before it expires you will automatically be billed for the full subscription. Now that you’ve canceled that subscription it will remain in effect until it expires.
For what it’s worth you are not communicating with Apple in these user-to-user community forums. Apple Support neither participates in nor monitors these user forums. We here are all just fellow users and have no ability to do anything for you.
If your request for a refund was denied by the vendor Apple will likely not refund either. Sorry
Request a refund for apps or content that you bought from Apple - Apple Support