In our Rec game last week the umpire called infield fly. He then reversed his call when the ball did not go as high as he thought. How do you handle a reversed infield fly call?

I don't think you reverse it. If the second call (reversed) was made verbally, stick with the Infield Fly call and rectify the situation, which would likely send the runners back to their original bases and the batter is out.

1st of all there is no specific height requirement for an IF other than a line drive.. the call should be made on any fly ball that could be caught with ordinary effort

this is one of the most common errors made by an umpire calling the IF to soon..

in order for a umpire to reverse a misapplied rule he would have to use his judgment as to whether the defense could have made any outs on the play and where the batter and runners would have been had he not made the call... also he should plug his ears while doing so