USPS hiring process?

I applied to usps in the towns south of Boston (where I live). I got a few interviews and ultimately got accepted to one of them, I got the email to accept the job, took the drug test and did the background check and it came back clear. I just got a phone call earlier 2day saying I got a job offer in Jamaica plain (which is a terrible area in Boston) and they said my other location I actually applied for got taken or some bs. What I wanna kno is am I allowed to apply to other locations while I m working in Jamaica plain I won t be an actual employee just a temp. As everyone is when they first sign up or am I able to transfer while I m a temp. I specifically avoided the Boston area while applying since the commute is terrible I m gunna hit rush hour going in and come home from work everyday