Could I take her to court?

I lived with a couple(two girls) and paid them rent. I was living there illegally as it was a one bedroom apartment. I paid her rent without having to sign any doentation. Just last week I paid her rent as she asked for it before the due date she had set for me. I handed her the money in cash and a few days later she asked me to move out because it wasn't working. She has since refused to refund me the rent. I feel betrayed like she has stolen from me and i thought she was a friend. She called me a f***ing b*** in a text message she sent me when i asked for the money back. I have kept all the messages. Should I seek legal advice? Lol where's judge judy when I need here?? Nice serious answers please.