The registration seems finicky. Working fine for some and then freezing for others. This is something only Samsung can help with. No idea why they said to contact Google. The beta is Samsung's. Through a Samsung app only on Samsung phones.
I have the banner to register and I did but it's been 3 days and no software update. Samsung said call Google, Google hung up, T-Mobile said call Samsung... What am I missing here!?!🆘
It is a beta and I don't think anyone can really help you. Some users report that after registering for beta, they got the update within minutes, other within hours and some other users got it within few days. Maybe it is stagged and if you are positive that your registration wes successful then you shall get it.