Firstly of course you can go after them. They should at least tell you where / how they got the photo, and it may be neccesary that you then have to go after that scource.
Hopefully though, they'll just admit a mistake and pay you retrospectively. I've had that happen before
Out of interest though, how did you find out about them publsihing them?
Finally I don't know if I should eat humble pie a bit, perhaps not, because I did say Ilike to see them cropped and printed larger, but now they are far more interesting and eye grabbing photos.
That crop made all the difference, from boring to dramatic.
But someone must have been able to see them full res to deciede to use them and of course get them full res somehow any way to use them.
