I wouldn't dismiss them yet. I believe they are sincere when they said they will call either way but I think they are busy finalising numbers, basing requirements and I also suspect they are being messed about by people not signing the contracts on offer and those that have accepted but may not actually start due to upcoming interviews with BA or other companies.
At a guess the lack of the NO or PFO letters/e-mails maybe an indication of their worry that many will jump ship or not start if they are offered BA/Emirates etc.
It is frustrating but hang in there. Their courses are running all through the winter.
Everyone I have spoken to has been very helpful and pleasant.
P.S. justanotherstat I would always keep looking and applying to others until you have a contract in hand! You have to look out for yourself.
Good Luck