Griff
I know from personal experience that your employer is an utter shambles.
Your post brought back memories from my days as a student/relief shop manager for FD in Manchester
In the summer holidays, I was willing to work 60-70 hours a week, because I was a skint student and I knew the money would keep me going during term time, but I felt pity for my full time colleagues who had no choice but to do this on a full-time, permanent basis.
I don't think I have ever worked anywhere where moral was so low. The pay was crap, we were woefully understaffed and hugely over-worked. Consequently, all the good staff left and, gradually, the quality and quanity of the new joiners became lower and lower (believe me, I have worked with some dorks in betting shops in my time). They simply could not retain any good staff - and that includes the trumped-up w*nkers who call themselves area managers.
Working for 14 hours in a shop that takes 1200-1400 slips per day with only a dumb trainee cashier to assist is f*cking hard work. When you know you have to do it the next day and the day after that, it gets you down. It is impossible to cope.
The ultimate piss-take was that, because I was only part-time (officially), I didn't qualify for proper Manager pay. So, for managing some of FD's busiest branches in some VERY dodgy areas of Manchester (Moss Side, Longsight, Gorton, etc), I was paid the delightful some of £4.90 p/h (minis a daily lunch-hour that I never had time to take and excluding enforced overtime spent trying to balance a till that had been operated by a dork for 14 hours).
I eventually left to work for Hills, which was better, but not by much.
You won't be allowed to take the summer off.
Your complaints will have no impact (except that your boss will earmark you as a trouble-maker and make life worse for you).
Nothing will change. FB has no interest in the welfare of his staff and his middle-management will not be grateful for anything you do for them.
You will eventually become demoralised, exhausted and bitter. Leave now while you have the chance.
By the way, have you considered working on the phones for Stan James? From what I can gather, their Wantage office is fairly near to you. The hours, pay, surroundings and conditions are all MUCH better than in shops. You get to watch the racing, you can't smell the customers and being at the heart of a bookmaking company is far more interesting than settling Doris's 10p Rapido bets.
Ex-Betting shop managers are just what they need. PM me if you want the contact details.
Good luck, whatever you do. Don let the bastards get you down!