Overview
Someone hasn't been returning your phone calls or emails as often as you would like, and you might be getting nervous. But have faith in them. You were there for them when they needed you, and they will be there for you if and when you need them, too. Right now, they just might be very busy, or even out of town! Give them the benefit of the doubt, and be patient for a few more days. Call them up one more time and let them know that you are worried. That should do the trick.
