I got an email to tell me that there had been a significant modification to my flight and to contact them on the given number within 48 hours. I tried several times, and each time I was reconnected to the correct department. Sometimes I would wait for 10 minutes before the music cutting out, once I waited for 2 hours - the music cut out after 40 minutes of waiting, but I thought I may still be on hold. I started to wonder if the staff were just sitting on "mute". Either way, terrible system, and terrible service. I still haven't been able to find out what my significant modification to my flight is... at this rate, it better be an upgrade to first class. I won't use Opodo ever again.