Yeah, what FBKSan said. The agent was wrong. How you fly to reach elite status has no bearing on how you earn your e500s. Once you reach 2P, every 10,000 BIS miles on UA earns you 4 e500s.

I don't know the frequency of the "sweep," but from my experience the e500s are always deposited into my account on Saturday afternoons. So, I would check this weekend if you recently surpassed the 10,000 BIS mark.