I asked Seetickets about the ticket delivery, and their answer was:
"Due to circumstances beyond our control, we're unable to get tickets to you
by the date of the show. We are advising you that your order will be
available for collection from the venue box office at O2 Shepherds Bush Empire
on the day of the performance from 1900 hours."
And I live in Finland. In the mail there were also some instructions on collecting the tickets. But I'm confused, cause 1900 hours is the time when the doors open for X, and it'd be nice to have my tickets by then...