Truphone's interview process seems child like, you'll first meet with a departments senior interviewer whos actually employing for the position. If you get through this round then you'll then be called back to meet with HR and IMO this is where things go wrong. HR normally come back with way to many questions, salary wars kick off since the team hiring is normally understaffed and want decent people. HR don't consider this and want to pay the lowest price possible, furthermore due to process I've seen around 90% of offers made rejected due to the candidate getting another job because it took so long to get an agreed offer out due to internal process issues.