Cancelling Stock and finding already charged invoices

There is no stock plan associated with your account only Acrobat.

I don't see any Adobe Stock subscription associated with the Adobe ID you are using here on the forums. If you have more than one Adobe ID you will need to sign in with Adobe ID/email address associated with your subscription. You can manage your subscriptions here: https://account.adobe.com

Please check if you do not have a second Adobe ID, that you may have used to book such a plan.

If not, or if you need assistance in cancelling, contact Adobe customer care. Adobe customer care can be contacted by beginning a secure chat session at https://helpx.adobe.com/contact.html?rghtup=autoOpen. Pop-up blockers need to be disabled! If the chat window fails to open, or is non-responsive, use a different device to start the interaction.
Support phone numbers may be found here: https://helpx.adobe.com/contact/phone.html. Please note that phone charges may apply.

For support via Twitter:
https://twitter.com/AdobeCare

(see also here: https://community.adobe.com/t5/creative-cloud-services/how-to-contact-adobe-support/td-p/11875703 or here
https://community.adobe.com/t5/account-payment-plan/how-to-contact-adobe-support/td-p/11843852)