I've been every year and they've been sold out instantly every year. People should have gotten them from the MSU site when they were available or try and see if they're still available.Definitely understandable.
I'll say this, I went to the Champ Classic in 2011 (NYC) and 2012 (Catlanta) and I feel like tickets were much easier to come by. This year is way different. Not sure what is going on.