Tercarley,
When you joined the company you were told that you would get staff travel for life. Was that fact in print on your contract of employment? No. I doubt you have an argument legally, and morally you come across as greedy and self righteous. My Dad flew for BOAC/BA for 30 years, hes not moaning about the changes, in fact his comments were "well, thats fair enough"
All the best,
PJ.