I'm afraid, I am on the side of the candidates here. Indications are that Jet 2 is a great place to work, so it is a bit dissapointing to see this...
My understanding is that the hold pool is where they place successful candidates whilst they await a course date and job offer. Everybody understands that requirements change but surely an explanation of "all courses are filled up and we are not able to offer a position before your time in the hold pool expires, so your status has been changed to unsuccesful in order to allow you to apply in 6 months time again", or words to that effect would be better than, you failed, despite us saying you were successful.
Recruiters sole job is to find new candidate for the company, so when you see unhappiness as seen here, they should take it onboard and see how they can improve. Perhaps candidates do not understand the function of the hold pool and it's limits. Again, this is down to them not getting the message across.
My experience with them left a bitter taste in my mouth. My aspirations ended at the roadshow when they said they would not employ me on a spouse visa. When I bounced that off BA, they said not to worry about the spouse visa as they would sponsor me for a work visa. Little acts speak volumes...
As someone who has been in the industry many years, I understand that an airline owes me nothing, but I believe I have earned a modicum of respect from potential employers. And, no, it is not entitlement, it is simply a two way street when you go down the selection process.