I have the same problem, Langeveldt
She only broke up with me 2 weeks ago and I started no contact, but then she called me a few days later, saying she is there for me and she doesn't want me to think she is cruel and cinical, because she is hurting too... We went out two nights ago and i was acting like her best friend, although it was incredibly hard for me. Then, yesterday she didn't even call me (i must add i had been away this week and she called me twice a day). I'm starting to think she was just feeling lonely the past few days because all her new friends were away. And when she got someone to hang out with, she forgot i was there.
Anyway, it's very hard for me to just be her best friend. We are friends for a reason, we have a history together, we love each other (or used to, anyway), it doesn't seem right for me to be the guy she "likes and apreciates most".