bideskochoro,
         sorry to hear that.Hope everything will be fine. I dont know that they can directly take you to airport and send you home. i believe that they will file some charge on you. But remember bro what ever they ask you remain quite tell your layer to answer all those shit. you just say "FOR EDUCATION" dont give other reason if they ask you why you work in gasstation?

Transfer your money to nepal. Incase they are sure to deport you they wont give chance to take your money out from bank. I heard they will seize all your property if they deport you.this might not be true. its just my thought.
 i was never in that situation. but i know some one got deported back in 2005. But his case was stealing money from work place unlike working like you.

sorry if i scared you. hey did those guys show you their identification? And did they handed you some ticket?
here also, one of my friend has same situation two guys came and they told they are from homeland bla bla bla and u are working illigeally bla bla but at last they said they are foking around. i dont know about your case.
 hope someone with similar situation will guide you in safe direction.
 stay cool.