How many games does your Badges page say have remaining drops? You appear to have sufficient time to have received all your free cards.

Duplicates will count against the total number of cards you're entitled to. If you get 4 of the same card of an 8 card set, further playtime will not grant you any additional cards.

To prevent abuse due to the new refund policy, you now have to play the game for 2 hours before the normal drop rates start.