Exact same thing happened to my parents. They had booked through Travelrep but their flight was holidays4u as travelrep only act as an agent. Is your flight meant to be with onur air? Onur air have had massive operational changes due to ash cloud. My parents just paid and extra £100 and went onto a Thomas cook flight as they were going to loose their hotel booking as the hotel couldn't change their booking by 4 days. The joys of DIY holidays Im afraid.

We recieved our tickets for mon 21st june from glasgow only to find they were for sunday 20th june 36hrs time difference. Phoned holidays 4u and were told mon flight is canceled.