Deal "Spend $X, Get a Y item free"

Hi,

Im trying to create a deal on the xstore database.The deal is "spend $75 and get one of item A as gift".

The item A cost $30. it works perfectly when I add other items that coset $75 or more.

But the problem is when I include the item that i am giving as gift to achieve the $75.

In this case if I add the item A 3 times xstore would charge the client $60 for the first two and then give the third one as gift.

The behavior that I expect is to charge to the client for $90 and then give time a fourth item A (free).