One Coupon Per Item

Hi,



I have two products I want to offer a choice of a free item when purchased.



I set up two coupon codes (one for each free item) that sets a code so if either of the two items are purchased they get that special item for free. The problem is if they buy both items that qualify for the special free item I can only add one free item to the cart. I have turned on/off “use multiple coupons” in the admin section and changed the setting on/off for “stop other rules” for the promotion I am creating with no luck. I can either add both free items for one purchase or one free item for both items purchased. Not a free item for each qualifying item purchased.



So, what am i doing wrong so I can have a choice of a different free item for each qualifying purchase? Or maybe I can't.



Hopefully this makes sense. Thanks.