You received a refund for your tickets which you were entitled to. They paid for your van ride home which they didn't have to do. NOW you want them to pay for your transportation OT the airport?
Had the weather been OK and the flight operated you would have paid for the ride TO the airport anyway. Why are you asking them to pay for it now because the flight canceled. I'm sorry you didn't make it to your conference but let's be realistic here. Your asking the airline to pay for something you would have to pay for anyway. Actually, had you made the trip you would have paid for transportation home too so they've already gone above and beyond, in my opinion.
Afternoon thunderstorms in New York City are very common. Newark, LaGuardia and JFK are a mess when they roll in. It's unfortunate but when it happens you just have to roll with the punches. You're already ahead. Let it go.
