Thanks, its not an ideal thing to have to worry about this close to the wedding. Its unlikely that I will get away with not paying more but we should get refunded for the lost flights. Whether I get refunded for that from the travel agency or the insurance is still unclear.
We are covered by atol though its unclear if they reimburse for just lost flights, so the most likely course of action is a claim through the credit card company. Thank god I paid with a credit card!