Um, not to burst people's bubbles, but if you checked your bills when Paizo sent the announcement prior to sending the first companion and the first Second Darkness module, you will see you were charged for the first companion. If I remember correctly, the total shipment was around $30 or so (the last of the Crimson Tide, first of the Second Darkness, and the first companion.)
You will also note that the Companions are also part of your Adventure Path subscription, so when the Elves of Golaron comes out with the third adventure path installment, you'll be charged the additional $9.99 as well as the $13.99 for the third path adventure.