Helps people who are having struggle with houes problems

I got a house lease and have lived this house since June 15. But I have to move out July 30. Due to the landlord dosent want me to live in it. And she wont give back the my deposit. i asked why and she said i had roommates before she approve them and i didnt give her the written notice 30 days before the day i will move out. But i asked her to meet and show all requriment papers but she delayed it and she said it is ok when i asked can i send the written notice little a bit later. There is way to get back my deposit ? please help me what should i do with this ? it is almost $3000 and i lived there only a month.