No matter what number you press (if you pressed a number), to either "win" the $100 gift card or be "removed from their calling list", you have just provided them with everything they needed... a warm-blooded human on the other end with a valid phone number. The very best you can do is not answer; the next best is to hang up when you smell a "RAT" (which is what they are!).
The absolute worse thing would be to give them your credit card info so that they can charge you the "standard $2.00 filing fee". If you adhered to this final procedure, don't ask anyone what that stabbing pain is between your butt cheeks!