Cornholio,
I actually stay well away from Shoreham, I really didn't have a positive experience landing there after I had passed my PPL. Not from ATC, not from the people supposed to welcome you (where they take a great big bite out of your pocket too), not from the flying school I visited there. Over the last few years, I have been making a note of the friendly places I have visited, and of the more unfriendly places too. Like everything in the UK you just need to sift through the cr*p to find the good stuff!
I have had a very positive experience learning at Biggin Hill (which I understand is a bit of a drive from you). Both Alouette Flying Club (bit cheaper than S&K) and Surrey & Kent. I found them both very welcoming, very nice and always got a cup of tea for you, even if you're on your first visit. Send me a PM if you're interested and I'll give you some tips on both clubs.
I wouldn't have spent all that money on going to a place I didn't feel welcomed, or a place that didn't feel was right for me. I went through quite a few before settling on Surrey & Kent, did trial lessons in many places too. You get the ATPL academies, the real flying "school", the club that tries to be the school, the club that is very much a club and the few instructors that have their own business teaching on their own plane. Not all will suit your style (or your pocket). I opted for a club that aspired to be a school for the training (as I wanted the availability of the instructor, as well as the slightly more regimented learning).
I am not sure where you are based, but there may be a few places I could strongly recommend such as Cambridge, Southend Flying Club, Alouette (biggin), S&K (biggin), Jersey Aeroclub, Goodwood.... amongst others. Always felt welcomed, always felt a part of the team, and always felt that it was money well spent.
I also agree that this kind of behaviour is crazy, especially after every single school out there having had such a bad winter! Surely they'd rejoice to have a new customer, and bend over backwards to get you hooked in!
I do agree however that part of the training is dealing with pressure, as has been mentioned. But I refuse to think that it is acceptable to put you under that stress outside of the cockpit environment during training.