This is very unfortunate but since you were not injured (thankfully) you should try and work something out with the Subway local store or headquarters.. You have to have damages in order to file a lawsuit and here, due to the lack of injury, you will probably not be successful with a lawsuit. I would just be thankful that you were not injured and consider any kind of compensation or gift from the Subway as a lucky bonus. It is very unfortunate that the knife was in the sandwich but damages are required for claims and lawsuits to be successful. Good luck.
NOTE: This response is general in nature and should not be considered legal advice. No attorney-client relationship exists or is formed by this information.
Answered on Dec 15th, 2011 at 12:44 PM