The UK T&C (which should be the same for the offer here), are as follows:
https://www.britishairways.com/trave...s/public/en_gb
Terms and conditions
1. Promotion is open to UK & Republic of Ireland residents aged 18 or over.
2. Promotional ticket prices will be the same as the total number of runs that Australia score in their first innings at the final test of the Ashes 2005 at The Oval; the number of promotional tickets will be limited to the number of runs that England score in their first innings in the final test of the Ashes 2005 at The Oval.
3. Promotional tickets will be available to purchase 1 hour after the first innings are completed; call 0870 850 2427 to purchase.
4. Participants are limited to a maximum of 2 tickets per call.
5. Promotional tickets are return flights in World Traveller from London to Sydney or Melbourne and includes all applicable taxes, fees and charges. Valid for travel from 19th September 2005 until 30th March 2005, excluding 9th - 23rd December 2005.
6. Bookings cannot be changed or refunded. No stopovers.
7. Valid on flights operated only by British Airways; excludes codeshare partners.
8. Flight bookings cannot be changed, refunded or transferred. All flights are subject to availability.
9. All travel is subject to BA's general conditions of carriage for passengers and baggage (copies available on request) and the notice and conditions of contract contained on each ticket and itinerary.
10. This promotion will be governed by English law and the English courts have jurisdiction to hear any disputes in relation to it.