Hello
Thanks for posting in the Apple Support Communities. It sounds as though you've got an active subscription that you're not seeing listed in your subscriptions or purchases on your device. Have you considered the information provided in article, If you want to cancel a subscription from Apple - Apple Support, under section: Can’t find the subscription that you want to cancel? If not, you may want to review and see if the suggestions there lead you in the right direction.
Should you find the subscription was set up directly with the company or developer for the app, then you'll need to contact them for help with the cancellation. Details on how to find the developers contact/support information is provided below for iPhone. If you're using a different device, please review the article for additional options.
How to contact an app developer - Apple Support
Contact the developer of an iOS, iPadOS, or watchOS app
1. Open the App Store on your iPhone or iPad.
2. Search for the app, then tap it. If you can't find it, tap the account button or your photo at the top of the screen, tap Purchased, tap "Not on this [device]," then tap the app.
3. The app's product page appears. Scroll to the Ratings & Reviews section, then tap App Support. If you don't see App Support, make sure that you're signed in with the correct Apple ID.
Best regards.