Student Attitudes

I was upset when I saw one of my student put up an advertisement taking new intake student to open class. I actually didn’t aware of this advertisement, it was my staff told me about this when she received the flyer delivered to her house.
This student (and yes it is so so soooo annoying and personally she is not really my student anymore) started with me in 2007 and she was hard working and supportive student. I always treat my students as my customers and I offer my best dance knowledge and ‘services’ (classes). Over the years this student grew in ability and asked more and more of me. Which was perfectly fine with me as it kept me on my toes! I was happy with her assisting in my classes to earn some teaching money. We had a great working friend relationship and she was happy with the agreement. I invited her to join me for things like grabbing a cup of coffee/lunch, working out more activities, promotion, new intake class, hafla (parties) & etc. I am completely open heart to share with her because I am interested in maintaining our friendships that will hopefully last a lifetime rather than merely accumulating acquaintances.
We were once close (2 years ago) and recently I noticed she has drifted further apart. For certain class activities, I tried many ways to call or send text messages to her but she never returning my phone calls or apologize for not being in touch. I tired my best to rescue our friendship and feel irritated when we actually met.
This experience hasn’t made me like or dislike her any more or less, but has made me realise that she is not true friend, just acquaintances. But in life and in belly dance community, I do not want to burn the bridge like break up with her, just...don't make the effort since I know it's likely to be wasted effort.
It's just that I think someone was wrong in doing something, there was no excuse for it, and so I don't 'forgive' them, but I move on. Being able to let go of it is healthy. Not always easy, but from my own experiences, definitely worth it!