What program do you have and on what computer operating system is it running?
Do you have a purchased serial number or just a product key? Whatever the case.....
Adobe is the only one who can take care of Activation matters for you. We are not Adobe. Just user to user.
Please contact Adobe via its Adobe Chat by clicking on the following link.
When it opens, click on the statement "Still Need Help? Contact us," to bring up Adobe Chat is discuss "Serial Number Issues or Activating My Product".
Remember to have all your details ready to give the Adobe Chat representative.