Unfortunately that is probably the airline charge. As it is beat the brochure it will be a dynamic package so the airline won't care how much you paid for the rest of your holiday. Sounds like a Ryain Air or Easy jet charge.

It will be the airline change fee, plus the admin fee that beat the brochure charge, which are detailed in their booking conditions. It's a lot of money for a name change on a £500 holiday! Perhaps it would be cheaper to cancel that person's flight and just rebook in the new name?

All bookings are subject to Ts & Cs of the organizer as well as the conditions of carriage of the airline which one has to agree to. For name amendments they state in their terms and conditions that “Supplier/agent costs plus £50 per person admin charge levied by COMO STREET TRAVEL” will apply. Regretfully unavoidable.

Cancellation and rebooking is not advisable as it will entail cancellation charges and new fare may also be more expensive; PLUS you might not get the same flight.