I'm a "temp"

For the moment, I'm a "temp" Spanish teacher. I work for a "company" that supplies foreign language teachers to elementary schools, both public and private. This saves the schools money as they don't have to hire a full-time teachers and pay benefits. It makes the "company" money because they take money from our hourly wage. I started with them part-time last year and the pay is great although the hours aren't much. This year, I've been "promoted" as I'm teaching at two Catholic schools and my hours have been increased, although the hours aren't as much as I was quoted this summer. They quoted me 27 and in the end I have about 16, 3 of which are at reduced pay, labeled as prep. time. I feel kinda cheated. What to do? I'm trying to do a good job and hopefully get hired directly by the school next year.