1st, there's absolutely no reason for me to not send the key once someone paid for it, so if your order succeeded, don't worry, we will find what's going on.
So, I have absolutely no trace of any order from the email you told me in my Paypal account.
Did you receive an email from Paypal to confirm your order was successful ?
Could you copy this email here, or better in the mail form here (so it'll stay private) :
If you didn't receive this email, could you check your credit card statement to see if you were actually charged for these $19.95 ?
Maybe for a reason or another, your order was not successful and Paypal didn't confirm it.