Jenny,
How did you book originally? If it was through Avro then you might have a case for their charges:
5. If you want to change or cancel your booking.
If you want to change your booking details in any way, we will try to help you, although we cannot guarantee that we will be able to do this. The following charges apply for changes in addition to any difference in price. If there is any increase in the fare available at the time you request any change, you will be liable to pay the higher fare. You will also have to pay any additional costs or charges incurred or imposed by any of our suppliers. We cannot transfer insurance premiums.
Name Change
Time before departure when
change request is received by us
Cost in £'s sterling per name change
84 days or more
30
57-83 days
30
29-56 days
30
15-28 days
30
0-14
50