Most Helpful Guy
Both of them can speak to who ever they want to speak to. However, this friend should know about your feelings for this guy and shouldn't make you uncomfortable. I like this girl and a few of my friends also have her number. They don't speak often but sometimes they do and I don't feel uncomfortable with it at all because I trust my friends.
If you talked to your friend and she knows how you feel about this guy and chooses to ignore you. Then, there is really nothing else you can do. I don't think she is a very good friend though.
Most Helpful Girl
Everyone can speak to whom they wish. Though, you already know that. If she isn't taking into consideration how you feel about this guy, she isn't a true friend. Real friends would never impede on what you want if you spill your heart out about whatever you desire. You have a right to be angry. Just don't go fighting, lol. I don't know, but be angry if you want. But ditch her. She isn't being a real friend,