Is it possible to undo the licensing of images?

I'm not sure, but I think that Kanika is no more in charge of this. It is however not possible "to change" the licence from one asset to a different one. I would suggest you contact customer care for this. Adobe customer care can be contacted here: https://helpx.adobe.com/contact.html - click the small callout at the lower right of the screen.

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