to be fair if someone corporate uses your image it's pretty good news as you can sue them lol or email them to pay you and they probably will rather than be taken to court. This is a great story though and to me it shows you are a true artist not just after money.

The true artists stay late on a photoshoot to make sure they are happy with the photos, they basically have a level of professionalism within themselves and something in them cannot leave a job till they have done everything they can to ensure that what they did matches up to that. The people that just work to the exact hours and don't really care once they got paid are the ones just in it for the money.