I'd call back, or email, and ask when it's best to call back to check status again. I'd contacted them the first time and they said I was under final review. The next day, they said they were sending my decision.
For what it's worth, mine might have gone a bit quicker because I applied last year so it was just a matter of comparing the two apps to each other to see if I'd improved wherever they wanted me to. Aside from that, I don't think they BEGAN reviewing apps until March 15 and they *did* say 2-4 months. So I'd say maybe give it a second try after May 15?