I went through the same thing last year. I called to confirm an appointment and the receptionist said "he's not going to be here by then. Start looking for a new pdoc." There were no other pdocs in the office that could take me either.
It's messed up how they can just dump us with little to no notice.
Time to look at other practices. I don't know if you have this, but my insurance company has a website where I can look up doctors in the area that accept that insurance. It's really helpful.
I hope you find a new, competent pdoc easily.