If a character has a white power. And in the power it says charge and leap climb. Does that mean when I charge get all the benefits of leap climb, or do I only get the benefits of leap climb when I take a move action. I tried to charge today but my opponent stated that I couldn't use the leap climb improved movement abilties during charge.

He was correct in that you can only use the passive effects of L/C when in a POWER action i.e. charge to the end of lower elevation and punch up (fine). If you were trying to gain any benefit of the MOVE portion of L/C this is not available as you can not give both a POWER & MOVE action at the same time.

If you wished to use actual IM: Blocking, Characters, Elevation or Hindering within a Charge (POWER) you can. -This is for any time you move a character (L/C, Sidestep, POWER Actions)

Just to clarify, you can still use the ability to punch regardless of elevation, but that's the only benefit you get using Charge. The rest of it is all its own dedicated MOVE action.