My employer pressured me to quit due to my religion.

after being hired at wells fargo bank, i was told i needed to work any days, they are closed on saturdays. by religion i do not work on saturday and my saturday starts at sundown on friday till sundown on saturday. after i told my employers i need to get off earlier on fridays in the winter due to short days they told me no and that it was my problem, and they made me feel like i was making up my religion . After i told them i will bring in a certiicate of proof from my pastor,they told me its no need and that they wont let me to earlier, she even joked about what can happen to me if i worked on friday night. i explained to her and she said it was my problem and not hers and that i dont have a choice, she then followed me around and tried to catch every mistake i made to find a reason to fire me,and pressured me to quit, thats what i felt because she told me i coudnt get off earlier a couple of hours and telling me its my problem. after tears i quit because i felt like i was being discriminated agaisnt my religion and made fun of, i even overheard her telling other co workers about my situation. she even told that noone will hire me if i dont work on saturdays. im not sure what i should do?? thank you!