Neetpan,
as said, it would be impossible to cater a flight so that each passenger had a guaranteed choice of each meal offered. Could you imagine the food wastage and the costs incurred by the airline. If an airline was to cater each flight the above way, your airfare would cost you A LOT, LOT more. Hopefully when you get into the flight deck you don't treat the crew the same way because you don't like the crew meal supplied!!!
Here's an idea, when checking in, request to be seated towards the front of the cabin so that way you may have a better chance of getting your preferred meal. Again as said previously, remember, it is an aircraft with a galley, not a restaurant with a kitchen and a head chef!!!!!
ps- have a look on the menu when you receive it and see if it states "aplogies if your preferred meal choice is not available", i know that's what ours says.
pps-if you tried legal action on this issue, i think you would literally just be laughed at.
Oz