They're making up new Ts&Cs after the fact again - "4. A Qualifying Flight is a single sector flight (i) with a BA prefix on a BA operated service", and ICN not on list of excluded sectors (neither are JER or DUB but they're also not honouring those). Very poor from BA - unless they're claiming this fell within a general promotion exclusion, as I booking class was valid...

"12. The following are not Qualifying Flights and this promotion cannot be used in conjunction with any offer, promotion, or deal including: (i) redemption bookings; (ii) travel agent discounted fares, child/infant fares or senior citizen fares, whether or not booked in one of the qualifying booking classes; (iii) bookings made with vouchers or coupons (e.g. shareholder’s discount coupon); (iv) tickets upgraded from any class other than Club World; (v) flights booked on BA125/124 Bahrain – Doha – Bahrain, BA073/072 Abu Dhabi – Muscat - Abu Dhabi, BA247/246 / Nassau – Grand Cayman – Nassau, BA253/252 / Nassau – Providenciales – Nassau, BA2153/2152 / Barbados – Tobago – Barbados, BA2153/2152 / Barbados – Grenada – Barbados, BA2157/2156 / Antigua – St. Kitts – Antigua, BA2159/2158 / Saint Lucia – Port of Spain – Saint Lucia."