In that case, sweets, you'll have to call a repair guy. There just isn't any way you can get around it, I'm afraid!
So sorry, r0opants... dunno how you folks stand the heat and humidity on "normal" days down there, much less in the middle of the hot season!!!
~~me~~
EDIT: Given the prices for coolant vs. the cost to replace, you will obviously be better off repairing your current unit. That's assuming that the unit isn't TOO old to be able to use the current coolant. Even so, there's a lot of places that sell the old coolant still, even if it's pricier.