Sounds to me either you used the wrong password or else, you didn't purchase it through LW.org but a scam site. How much did you pay?

You are aware that pro offers 6 months of free updates & support only aren't you. If more than 6 months has passed since you purchased it then your account details will have been removed. It's up to you to keep a backup of your installer or else upgrade your pro after 6 months at a discount.