It's funny really, student pilots will put up with all sorts of crap that they would never consider in any other field of endeavor. Poorly maintained aircraft, bad instructors etc. During my training I put up with a verbally abusive instructor with an ego the size of a small country, eventually I walked away. Students MUST learn to be more demanding, I mean you're forking out a fortune to this company so they should provide you one main instructor who you're happy with and provide a level of service appropriate to the investment. They are not doing you a favour!
As for Cabair...I have to say that they are the most mercenary flying school I have ever come across and if given the chance will quite literally sell you the time of day. I would avoid them if at all possible. From friends of mine training at Elstree I hear about all sorts of crap that they put up with like never having the same instructor twice in a row.
If you don't mind a bit of travelling I would look further afield for a suitable school with which to train, don't limit your options because of convenience.
Phil