Originally Posted by
ExpatSomchai
Problem with changing the flight is that I have a non flexible BA flight booked for the return
Unfortunately, that is part of the risk inherent with buying separate tickets. Airlines can and do change schedules. We might not like it but it is their right, and if they do so with enough notice (more than two weeks for flights subject to EU261/04 regulation), no compensation is due. Again, you can ask for a full refund, but precisely because of your inflexible other ticket, this presumably would not help either unless you can book with another company which timetable would be compatible with the timings of your other itinerary.