Sorry to reignite this thread, but as it is very much related didn’t want to start a new one.

Owing to an unfortunate change in Mrs Wilsnunn’s work schedule, we have had to alter our upcoming trip to come back a day earlier and from a different city (INV-LHR instead of GLA-LGW). The cost to change the reservation was significantly more than booking new tickets for the return flight so I have done that instead, I think that the taxes on the return flight would have been £24.87 each but I cannot determine whether there is an admin fee for this or not and as I only want to cancel the GLA-LGW booking instead of the whole booking I am not entirely sure how to go about getting the refund for the return leg