Registering an apple product

I've been trying to register my new beats 3 headphones for days now and I can't get the website to work. I was hoping someone could help me fix this problem so I can make sure they are registered under Apple care. I have the serial number and date they were purchased and everyone I've tried all different computers and my phone to try to get this done but the website keeps coming back with different problems. Thank you for your help!