It isn't, really. This is clearly over your moral line. Tell your management that. Yes, you have a contract. Yes, there will be penalties for defaulting on those terms. But there are also penalties you will suffer personally if you continue with the project. Think about it... why should you take on that personal burden on behalf of a company who would fire you tomorrow if you stepped over any of a dozen different lines? And... what will it take you, personally, to erase the image of someone getting scammed by your product and design? I don't know what type of brain bleach you have where you live, but I am unaware of any product or service that will quiet my brain-weasels as I lay in bed at night, unable to sleep, and worrying about something I have done... In the end, the customer still has a need, and you still have a contract. Contracts can be negotiated, and this one clearly needs to be re-evaluated, collaboratively, with the customer. "We cannot morally perform this work. Here is why. Here is what we propose, and here are the contract terms we need to modify to make this happen. Let's talk." If all you get from this is to leave the company with your integrity intact, you still have made the right choice. Yes, but it's complicated.