My company is a small electrical subcontractor. We are running into some material procurement delays because our GC Customer has been slow to release payments. According to our contract, the GC has to provide us with a formal notice to cure any issues, with 72 hours of time, and up to another 48 hours on a contingent and discretionary basis. No formal notice to cure was provided, and 3 days later the GC purchased all of the outstanding materials, said they would be backcharging us for the cost, presumably plus a 15% administrative fee. This type of action wasn't stipulated in our contract documents, explicitly or otherwise. Now the GC wants us to essentially perform labor, at a loss. Is this legal? We should obviously contact a lawyer, but I'm looking to get a better feeling about the legality of these actions before doing so.