How to cancel the Free product in the order with Buy x get y applied promotion

Hi Experts,

I am working 6.7 version with promotion engine

When customer cancel the any product of x in Buy x get y promotion after placing the order.I want to cancel free product(y) along with canceled one.

when i am executing the recaluclatewithPromotions automatically undo the promotion if promotion is not qualified for current live entries.But only in case of Buy X and Get Y not working and that to i want to cancel the free product.

Please guide nay me how to achive this.