No. Your work was not stolen. No part of "take (the property of another or others) without permission" occurred. Your property was not taken. The software of which you speak isn't property in any real sense. However, you had an agreement, and for whatever reason, that agreement was violated. The reason the agreement was violated can't change the fact that it was a contract dispute, not theft. What you are trying to do is redefine "steal" and/or redefine "property" so that one can "steal" something without taking it, or depriving you of it. This is a point of view that lots of money and marketing is going into, but all the propaganda in the world won't change the fact that you are wrong. It isn't stealing. No physical property was taken from you without permission. You gave permission, under an agreement, to be paid and that pay was not forthcoming. You could say they stole your money. That would be theft.