Complaint

How can you "not know about it" for 19 months? You can contact Adobe to make an appeal for a refund, but I think it is very unlikely to be taken seriously due to the length of time that you have accepted and paid the monthly charge.

Hi John,

This is a user to user forum whith some Adobe participation.

So as a user, not being an Adobe emplyee or otherwise working for Adobe, I have some remarks:

If someone charges my credit card for 19 months, and I did not do something to get known the charge, I have a problem with my control about my finances. A latest at the first charge, I would investigate the charge and get the subscription cancelled.

Also: you can't blame Adobe not to taking action if you do not use the subscription you booked. 

Probably, 20 months ago, you took a subscription of an Adobe product, and as an addition you booked a 30-day free trial for Adobe stock, that you did not cancel in time. You were send at that time an e-mail with the terms and conditions of the subscription(s) you took. 

If you want to negotiate a refund, you will need to 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, you need to accept cookies! If the chat window fails to open, or is non-responsive, use a different device and/or browser to start the interaction.

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)

Important: Adobe does NOT contact you unsolicited by e-mail or direct message. If you get contacted by direct message from a person, claiming to be an Adobe employee, look at that profile and check if they bear the “Adobe Employee” marking under their name. Adobe support does not use Skype to give you support.
If in doubt, ask the forum.