I don’t remember signing up for Stock and found out I was being charge $30 per month. And now when I

Look into your e-mails, and you find confirmation of the plan you've taken, probably together with a Creative Cloud plan. The early termination fee is because you have an annual subscription, and you want to terminate early. That's not bizarre. That are the standard terms and conditions.

If you did not use the plan, contact Adobe customer care and negotiate the cancel, free of charge. You may also ask for some refund, depending on the age of your subscription. And in the future check your credit card charges early on. It may help your budget.

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)