zero appreciation over the years....done with subbing or this school

I often sub at the same school, and it's the only one. While I have a good relationship with teachers, the school is a mess. The principal always pulls subs to cover out IA's or teachers. Subs don't come back because of this pulling during the planning period. I have worked my butt off for them, and I know the kids, I teach, work hard, etc. But I feel so unappreciated. I get a brief thank you at the end of the year and that is it. Never told to participate in any of the teacher food they have out on occasion, etc. I think I am done with this school. I get that we are JUST SUBS, but honestly, where is the appreciation...??????

I was out for several months this year with cancer surgery, and the assistant principal and the front office woman who books the subs. Not one welcome back at all. Just business as usual. It made me realize I am just a body. I cared for those kids and that school, and honestly, I realize they don't care who subs. Does anyone else feel this way about where you work often?