I'm still being charged for an expired app subscription

Your Apple account is merely being used as a method of payment, the subscription is with Discovery. If your account shows an active subscription but you are having an issue with using Discovery's app to access the service then you need to reach out to them to investigate. However, if they are unwilling or unable then you can cancel through your Apple account and request a refund.

If you want to cancel a subscription from Apple - Apple Support (CA)

Request a refund for apps or content that you bought from Apple - Apple Support (CA)

Asking for help by accusing Apple of fraud is not the best way to get help. No one here is an Apple employee, just users like yourself trying to help one another. The forums are not official Apple Support and Apple does not monitor.

[Edited by Moderator]