I'd need a lot more info to give you a definite opinion, but in general, if you led them to believe that you were hiring them, and they went ahead and did work that they reasonably believed they were going to get paid for, then you might be on the hook. On the other hand, if they went ahead and acted on an assumption or a misunderstanding, that's their problem. Depending what state you live in, you may have some grounds for defense based on the "Statute of Frauds", which provides that some contracts must be in writing in order to be enforceable.
Answered on Dec 23rd, 2014 at 2:38 PM