Originally Posted by corporate-wage-slave

This is a really unfortunate one. Firstly can you perhaps check whether KOS (KGS) is an alternative on BA for the Monday? Or DLM? But in this scenario BA will never rebook before travel unless there is a BA service, or sometimes a EI or IB, which presumably there is not. They would not rebook on to easyJet even for a same day cancellation either. The only thing you can do is keep asking for alternatives on Monday, and if BA refuses to assist with this, leave the booking - don't accept Sunday in particular - and then bill BA for easyJet after travel is completed. CEDR is almost certainly willing to back you here. If there is a flight on Tuesday then BA can be held responsible for the extra hotel night.