I can see your seats.

http://www.hongkongcard.com/webedito...0647_98580.jpg
http://www.hongkongcard.com/webedito...0716_74864.jpg
http://www.hongkongcard.com//webedit...4215_84328.jpg

I was afraid I'll lock your seats, so I changed dates to 18-30/1:

http://www.hongkongcard.com/webedito...1813_31358.jpg

Tried booking it:

http://www.hongkongcard.com/webedito...1439_10220.jpg

Is it spitting a dummy because of the transit? In any case no solution but to call MPO centre and have the redemption issued by phone.

No availability on ba.com