I gave a despoit for a apartment and change my mind a week later and the landlord do not want to give me my despoit banck tell me she want to keep it. Can you give me my right. She told me she can keep the my despoit . Is her right

Depends on the circumstances. A deposit given to secure an apartment is usually not refundable.

If you gave them a deposit you rented the apartment and would owe the first month rent at least.

And often a deposit is done to hold it for you, if you latter don't take it, they keep the money,

It sounds like you just don't understand rental rules.