Reactivating Cubase

I switched computers and cannot reregister cubase on other computer.I uninstalled it from the other computer and tryed using the old activation code and license number. They do not work.I tryed contacting customer service but no response from E mail yet.They I guess do not have a phone number for the U.S anymore. AAny help would be appreciated

The procedure is quite well explained in the Steinberg knowledgebase and in your “MySteinberg”-account.