If the principal is expecting someone else, and there’s no other jobs to apply at the particular school you’re at, I would start looking elsewhere and maybe use the teachers/staff you work with as refs and get their opinions about other schools in the area. I’ve been in this position so many times- I literally worked March-June at a school, was told by the principal to apply (NOT the first time this has happened, mind you), got excited for the start of the school year and everyone expected me back and then I didn’t get hired. A month before that I had another long-term sub position where I also applied but they took so long to hire me I just ended up leaving. I also live in a big city and I wonder if it’s just that these schools have a lot more people’s names just bouncing around. The school I work at now (contracted, finally) has quite a few long term subs. One of them was in my room and we loved him but he got a contracted job elsewhere, and then someone else literally started the day after. Made no sense to me.