need help

I have a situation that I need help and direction with, and I am hoping some of my fellow nurses will point me in the right direction. So here goes....I am a Registered Nurse working on a Cardiac floor. I have been at this position for 13 years and have been actively looking for a new challenge. I happened to find a posted position within my organization that I thought would be something new and different, which is what I was looking for. My organization is going to be changing to EPIC soon, and they were looking for a variety of people from within, nurses, physicians, lab, administration, etc, to providing the training to the current staff. I applied to the position and waited to hear something. I didn't hear anything for about 2 weeks when I received an email from Human Resources saying that they would like to speak with me regarding the position. I work only part-time, straight night shift, so it had been about 4 days between HR sending the email and my response, giving my cell phone number (which had already been included when I applied). I heard nothing in response for about another week so I called HR and let a message for the person who emailed me. I haven't been job hunting for quite a long time, (I have worked for this organization for 23 years!) so I didn't know if this was common to have such a long time in between contacts and I didn't want to appear as though I was hounding this person, so I waited. And waited......Not hearing anything back through email or phone call, I called again this morning and I was told by HR that they had tried, unsuccessfully, to get into contact with me, that since they never heard back from me they assumed I was no longer interested, and that the slots they had available for interviews,(that were set up for this week) are all filled. Basically, she told me I am out of luck. I nicely told her I was surprised at this, and asked how she tried to contact me other than the one email I received. She told me that she has in her notes that she tried to call me, but when I asked which phone number she called, she said "someone else is on that computer and using that system right now so I can't give you that information". I told her that I emailed her and left a phone message for her and that I received no reply from her. Again she said that all of the interviewing positions are filled and they are no longer looking for candidates for that position. I can't believe it. I asked if I could speak with a supervisor about this and she said she would forward my request.

I feel I would have been a really good fit for this position due to all of the experience I have with working for this organization for 23 years and feel like I at least deserve an interview. I am waiting for the supervisor to call me back but I am unsure as to how to handle this. I really am shocked and feel this was handled in a very unprofessional way. I need guidance and help. Should I just chalk it up to something that is not meant to be? I usually know how to handle things, but I am very upset and surprised, and I want to handle this the best way possible without alienating myself or anyone else. What should I do??