"expedite" means do not dawdle, be quick. What you wrote looks pretty much like a reaction to a controller saying "immediately". If that was the case, the reaction was good. To a mere "expedite" you can react with 2.500 fpm, especially as you seem to fly an A320, a not very liked acft among controllers for its unforeseeable climb-profile. To americans driving it I can say something like "disregard economy and fly it like a man", to Englishmen I would say a noble "expedite":