Register a device in my iCloud account but the device is not in my posession

I purchased an iPad for a friend of the family and they have not paid for the device after seven months. I have my receipt with the serial # and I purchased AppleCare+ for the device. I would like to register the iPad having never logged into the device - I assumed I was going to get reimbursed within a couple of weeks.

Do I have any options to register the device remotely? I am guessing not, but I have never been in this situation before so I don't really know what my options are.

Any thoughts greatly appreciated :)