International student wanting to create a new line on AT&T

Hi. I'm a 20-year-old international student. When I visited AT&T store last month, I heard from one of the sales representatives that I can get a new phone with a new plan on AT&T without paying a deposit. So, I placed an order online today, and it didn't work out. I have a SSN# which is only for on-campus work, and the email says I need more information to provide. Anyway, my question is can I really get a new line on At&T without deposit? If I have to pay a deposit, how much would it be?