It depends on the terms and conditions you signed up to when you paid your deposit. I would expect most holiday companies to refuse to give a refund if you cancel late, however unfortunate the circumstances, when you haven't got travel insurance/cancellation insurance. If you want to send someone else in your place, though, I'd hope the travel agent would be flexible. But I think there would be quite an admin cost to them for changing names on flight tickets, etc and it would be reasonable to charge you an admin fee.