Amazon Prime won't cancel? Tells me to use Google Play Store but I didn't sign up the subscription there.

Basically I signed up for Amazon prime a few years ago through the site itself. I decided to try and cancel it today but for some reason it keeps telling me to go through Google play. I have not signed up for prime with Google play so it literally will not show up on my account.

How can I cancel my subscription if it keeps telling me to cancel it through something I didn't sign up with? I initially subscribed through the site itself. Please help me figure this out. I know I have the right account on Google play store and the right Amazon account.