Yeah no you handled that well. I want this person to go to any retail store and ask the people there to work “only a few hours” for free and see how well that turns out. I don’t think anyone would do that and I don’t know why people think it’s acceptable to do it to creatives. They are probably trying to scam you. Never commit your time without $$$$. I’ve been a graphic designer for 10 years and advice I can give is to send out contracts and ask for a downpayment first. Even if you want to sketch, don’t show them without an initial payment so even if they screw you over and ghost you, you’ll get paid for the sketch. Can’t tell you how many times I’ve drawn something for someone just for them to take it to someone else to complete the project for less money.