I see that maximus is in Britain. So who knows, maybe having the same issue I was?
I was dutifully buying free range chicken breasts and chickens (at great expense) until I realised that at least half the time they were coming out really tough and chewy. Which makes sense when you think they are getting a lot more exercise than non free-range chickens. I tried all manner of cooking techniques including using foil and poaching. It just didn't make any difference.
So now, I buy corn fed, quality assured chicken with the "Red Tractor" logo (which assures that the care given to the chickens is to at least a certain standard). Not as good (ethically) as free range, but the chicken is a lot more tender!
I don't feel good about it, but I can't justify paying a small fortune for chicken that is horribly tough.
Anyway, just a thought.
(I still only buy free-range eggs.)