The rights of an employee upon termination without a reason

Hello,

Good day!

Please I need some advice!

My employer canceled me automatically without a valid reason. I have already finished almost 8 months and they brought me back to the agency.

The agency sent me again to another employer. Can I leave the agency?

My employer told me that I can't leave the agency because they paid for me. They canceled me without a reason.

I want to know my rights.