Our apologies: there might have been a temporary glitch. Please try the instructions here to restore purchase:
If it doesn’t work, please let me know your (1) Alfred account and (2) the receipt you got from the confirmation mail of Google Play Store/App Store/PayPal. I will make things right for you as soon as I can!
※ Please note that the upgrade goes to the account you were logged in to Alfred with at the time of the upgrade. Make sure you log in with the account that you bought Premium.