Originally Posted by Tafflyer

This is a significant change but far enough out to not warrant any EU261 compensation. You have the right to refuse the rebooking and if no acceptable alternative is offered, to refund the tickets. Not sure I understand how both Cheapoair and Orbitz are involved, do you have multiple tickets for journey? If so, you may be out of luck regarding changes or cancellations. You will also have to make any contact and changes via the OTA's which will make your task that much harder.