Like I wrote: You didn't *have* to do the training path you attempted - and perhaps completed (and if completed, good for you!). You *chose* to do it, along with the upfront payment, in the hope that you would leap into the cockpit of a shiny jet.
Some amount 'in credit', as you put it, is not necessarily the same as a complete payment up front that lacks even a basic funds protection or preservation mechanism. There certainly isn't a *requirement* to do training via an integrated route. Non-integrated is also available - and nearly always cheaper. If you can't negotiate a satisfactory protected payments program at an integrated school then walk away. You don't need their services as much as they want your money. There is always an alternative way to train.