Cabair forbid their instructors to instruct elsewhere whilst under their employment. You WILL be expected to do more than 20 hours per month!
Look, would you trust an employer who is not even available for you to talk with? Read jakjakjak's post again and you will see the lengths the poor guy has been to in order to check about his employment status AFTER being offered employment!
My word, how many warnings do you need in order to smell that something is not right? If you cannot detect something drastically afoot with this arrangement, especially after the terms have been altered WITHOUT even consulting the person who has been offered employment, then I question your sanity to walk the streets, nevermind fly an aeroplane!
I would run now, before you get yourself into an almighty mess. No axe to grind, couldn't care less for the firm (I think this shows) but simply would hate to see someone get themselves into a bad situation.
There is an instructor shortage, if you cannot afford the FIC then seek a lender AWAY from aviation. It does not ring true that you have no way of obtaining money after forking out £40K. If you did not plan for either a type rating or FIC following training then you really did not do sufficient research into the game before you got the bread together to get where you are now.
VFE.