Is there anything I can do about this help needed?

[Martin]

I got divorced earlier this year after 5 years of putting up with an unreasonable father in law. My father in law tried to control my married life to the point where I got depressed. An example of this is his continued pressure to force my wife to holiday with him in tenerife nothing wrong with that in itself but at the time my son had been born premature and needed a oxygen bottle to survive. Since we went our separate ways he has tried to side line me out of my sons life. When I was in the process of divorce he used to enter the marital home and look through my personal letters and bills invoices etc. My post went missing, he followed me around in his car. This Christmas for the first time ever after months of hard work and relationship - trust building on my part I had been promised that my son would be coming over Christmas day, up until this point her family have always made sure this was not the case. I found out yesterday that her father has decided to go away on the week leading up to Christmas, my ex wife has decided to go and booked it with out consulting me without my consent returning on Christmas eve. While I want to see my son I know that the long days travel will tire him out to the point of exhaustion, he suffers from Cp and other medical problems. I phoned yesterday and told my ex wife to forget it as I am concerned that he will not be in a good state to enjoy it. I asked to change it to boxing day. She has refused. Which now means that I will not see him at all over christmas. Am I being unresonable. I have done this only out of concern for my sons welfare.