I would like to unscribe Adobe Stock on may account, but there no option in plans to use cancel button
For self cancel: Cancel your Adobe Stock membership
You can't cancel, however, if you have payment issues. You first need to solve those, and cancel afterwards.
If this all does not work for you, I suggest you contact Adobe customer support. 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.
Support phone numbers may be found here: https://helpx.adobe.com/contact/phone.html. Kindly note that phone charges may apply.
For support via Twitter:
(see also here: https://community.adobe.com/t5/creative-cloud-services/how-to-contact-adobe-support/td-p/11875703 or here
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 look, 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.