Is My Anger Justified?

I have pretty much for the past month been able to offer grace and forgiveness to Lillian's parents. Lillian was never really ours to begin with regardless of the words spoken to us, the promises made and the feelings of love we developed in a matter of hours. But I found myself last night and this morning angry at them; no, more like furious!  I want to write them a letter and ask what they were thinking, to beg them to never do this again to another couple.  How could they sit before us proclaiming to have watched a close relative struggle with infertility and failed adoption, that they wanted a couple who didn't already have any kids, that they would never do to us what had been done to their family member.  But what good would that do. They could care less what we think. They don't know us from Adam. (Except for knowing our hearts and souls and our complete infertility story, my hopes and fears with adoption and my struggles with the thought of what I am missing by not carrying my own baby and a great detail about both of our families). When I really let myself think about it I get pissed off and worked up about it all. They had every right to change their minds. Lillian was not ours to take but theirs to place. It is the fact they did not have the decency to tell us that really gets me angry. All it would have taken was one phone call to us, Heartbeat or the lawyer. A simple, we are sorry but we've changed our minds.  I am left wondering if my anger is even justified?  Am I allowed to be angry that I have lost something that was never really mine to begin with?  Even though I want to be angry and bitter I must force myself to let it go. I am choosing to offer grace so I must chose to not be angry.