Hi All

I have an ex-OSL (one of the viking fares) booking to SFO in I class. I've already flown the outbound and am currently in SF.

My work has asked me to change my itinerary to instead stop in New York for a few days to do some meetings before heading back to London (original booking is direct SFO-LHR-OSL)

I've checked out potential routes and see I-class availability (on a dummy booking) for SFO-JFK and JFK-LHR routes on the dates/times I'd like.

I just called BA, and they're pricing out the change at almost GBP 5,000. They say the reason for this is that when you make a change to a partially flown itinerary that it has to book into J class and not I class.

So am I screwed here on price or should I keep calling until I find an agent that can change my itinerary and still book into I-class?

Thanks!

Edit (in case it's useful): The agent said that when he tried to price in I class he got an 'error' saying the fare class was not available. He then said that was because the itinerary was partially flown.