So this has really got me. First time in World Traveller for a very long time, LHR-PHX on Friday. Booked WT at short notice and was offered a few days later, and accepted, a WTP upgrade outbound for GBP297. Clicked through to the final payment and an error message came up saying ''it is not possible to change this booking online, please contact our office blah blah.'' Tried again, the offer was still displaying in red at this point but when I actually clicked through to the payment the final price was now GBP1680 (!!) for a one way upgrade to WTP. At this point, with the fear of a first time in traveller for a nearly 11 hour flight, I really wanted to take the upgrade. So I called BA and spoke to a lovely lady at EC who confirmed that the seats at that price had been taken, and that the only avaliable upgrade to plus was indeed GBP1680 one way and that was because only fully flex was now avaliable. She said there was a glitch on the website that still offered the promotion when it was no longer avaliable. It remained displayed for a further four hours and then vanished. 36 hours later - guess what - an upgrade to WTP appears again for GBP297 and I nearly took it as it actually seemed to work this time and took me through to the final payment at that price. However, now a bit grumpy with BA I decided to do a dummy booking and found out that WTP is filling up with only centre seats avaliable, where as I'm in 52H an aisle seat at the back of what looks like an almost empty WT cabin - so decided to take my chances at the back of WT which looks almost empty rather than paying for a seat in a jammed WTP cabin. But it has left me wondering is this an IT glitch or BA just trying to mess with me or what?