Pardon my disbelief, but I don't think anyone can be stupid enough to not invite their "best friend" to their party, and have it where the uninvited "best friend" works. I think you're either overestimating your bond to the person, or she's trying to tell you to get lost.

IMO you are better off without that group of friends!

don't you ******* call that bitch your best friend again. I don't care if it's a he or a she. Still a dick.

Maybe it was because they knew you would there

Perhaps she knew you were working, and so chose your restaurant so you can be a part of it?

They may be your best friend, but you aren't theirs.

considerig you are best friends they clearly knew you were working then so rather than invite you they went to your work xD

Maybe they didn't invited you because they knew you would be at working, so they picked your restaurant for the party so you could be there singing along with them.

interesting I'm that persons who trust to not get invited out with friends. I'm weird I know.

Well, you were at work. Maybe she knew that you had to work, and the only way to include you was to have the party at your work. I don't know why your upset if you had to work anyway. It's not like you could've gone if she had invited you.