Ask them to take it down. If they don't do that, use the DMCA takedown process to have the photo removed. You could try invoicing them for their usage and see if you can get them to pay, but not sure it is worth pursuing it as a copyright infringement lawsuit if they won't pay willingly. However, under US law, willful removal of a copyright notice is subject to a significant fine, so that might be an avenue to consider. Would consult an attorney regarding that.