Actually, I was just there in April, and if you go thru passport control in the center area, it will be to your left, kind of tucked in a corner, but MUCH better signed and known of than back in 98. (It's almost as if you'll be doing a U-turn to your left to get to this place, it's a small window.) THEN if you'll be receiving the money right then and there, you go across the isle to the other area marked VAT, and they'll give you your money. If you'll be receiving money later (like on your credit card froM El Corte Ingles), there's a mailbox right in front of the first window.

Buena suerte!!