We have a return DUB > LHR > JFK booked for July, but our options have opened up and there are better flights available for our travel to BOS.

I have two options I think:

1) cancel and use the voucher to buy the new ticket - how long does this take for me to see the voucher available for use?

2) ring up and amend.

does anyone have a view on which is the best option for us?