The very name "Red Carpet" refers to a way of offering a reception of honor and dignity. You got anything but.

If you write, make the issue a matter of attitude. You might mention your opinion of the shabby chairs and carpet and/or the denial of drink chits. But despite these minor offputting experiences, you might say, the lack of civil treatment made your entire trip an unpleasant memory, certainly the kind of bad memory which affects your thinking when it comes time to book another international trip.

Such a letter might do more to bring the most important kind of changes for the benefit of everyone (like sacking the horrid meanies at ORD's C terminal RCC, the B and F terminal personnel don't seem to have such an ugly attitude). And if you are offered any kind of compensation, it is likely to be more substantial than drink chits.