They simple said you'll get free update when it goes Gold. No actual promises were made.
It doesn't matter if they actually promised it or not, as long as it was directly implied! This is the same reason why there are bait and switch laws. You cannot lead a person to believe one thing, and then do another. A seller cannot lead another person to believe they will receive a product at a certain time, and then not deliver it. If it was implied that updates would be available, and then at a later time they were not made available, then the seller has broken the contract and it is void, and at that point the buyer has a right to recoup their losses. As far as the OP's question, I would say give the part that you bought away for free, and then charge for the parts that you put time in to fix/update or whatever you want to call it, to recoup your losses.