This happened to me several years ago. I signed up to Audible's free trial, got a single audiobook, then decided I wasn't really an audiobook person and forgot

This happened to me several years ago. I signed up to Audible's free trial, got a single audiobook, then decided I wasn't really an audiobook person and forgot about it. Then many months later I noticed I'd been charged monthly (I think ~$10 USD or so?) for a service I never even used, and I don't remember even giving my card details for (it is my longstanding policy never to continue with "free trials" if they ever ask for payment details during signup, exactly because I know I'll forget and get charged). It turned out to be the card I use with Amazon -- I think I must have signed up for Audible using my Amazon account and they automatically used the card I had saved with that, without telling me. I don't remember the full details of it but I ended up hours on the phone with Audible trying to claw back my money.