Got disabled last year and I am being punished for it

I worked in retail last year and got disabled. I had to start working in the call centre for the same retail chain and they are cruel to me. ​ Their scheduling is humiliating. I have been in a fight with them since they hired me since I have to work every weekend. They schedule their other workers with decency and dignity but I'm that inferior person who they hired so they can enjoy their weekends. ​ I can't take this anymore.