Is there a contact to have the number of activations on my Adobe account reset?
Assuming I'm understanding what you're trying to do... you can actually do this yourself!
Sign in to your Adobe ID. Once signed in, select Manage Plan under Plans & Products. Then, on the right hand side, you will see your Activated Devices and can choose which ones you'd like to Deactivate. I hope that helps!
Which product do yoused? A membership or eBooks?