Roommates: Is Verbal Agreement to Be Roommate Binding in New York

I responded to be a roommate (sub-tenant) advertisement by a Main-Tenant (lease holder) to rent 1 of the BR in 3BR apartment in New York city apartment complex. We had verbal understanding of my being her room mate but she will submit my application to be a legal co-tenant to the landlord and I paid advance 1 month rent and security deposit amount of $3900. 10 days later I got layoff notice and I informed the Main-tenant that under the circumstances I cannot go through with the deal. We had not signed any written lease or agreement. She refuse to refund my money. Can she keep my money? Does she have legal case to keep my money or demand implied 12 months lease rental?

Roommates: Is Verbal Agreement to Be Roommate Binding in New York