Admittedly, I am not a lawyer, but:

Why should you care about a law in Libya? There is a contract for transportation between TG/LH/Travel Agent (however their contractual arrangements amongst each other are) and you. So they should honour it. If they cannot, because of a law in Libya, they should have to pay you damages. Of course, they could also simply issue a new ticket for the remainder of your journey.

Ask a lawyer for his opinion, but I cannot imagine that they would have the right to refuse you.

SmilingBoy.