Can't cancel account

I keep getting billed for Acrobat Pro but my usual email login does not have a subscription.  I can't cancel the subscription because I can't find the login that was used to purchase it in the first place.  I've tried every email I've ever used.  Nothing.  I'm not sure what else to do but it's driving me insane paying $15 every month for something I'm not using and can't cancel.