Far be it from me to cast aspersions on suppliers, but - I suspect that the trees might have dried out before you bought them. I buy in my stock straight from the ground and heel it in immediately. Even then some plants suffer. Beech is one of the worst and I am reluctant to sell it after Christmas, and withdraw it from sale after January, potting it up instead. The taller the trees, the longer they take to recover. They require a free-draining soil, but, of course, don't want to dry out. Keep at it another year or so. Try a mulch in about April, to conserve moisture (it'll save you some labour). A thought - are you near the coast?

another thought to the one above. what is the soil like? same depth? rocky stoney areas etc?

Thanks. I should have mentioned that this is the second attempt - the first ended in similar circumstances, the nursery replaced the plants and I got more mature ones this time and put them straight in after soaking. I dug the soil out and replaced with good topsoil and organic matter before planting. I have also mulched each spring.
I do live about 500 yards from cliffs by the sea but not directly overlooking the sea - I did wonder if they don't like coastal areas - there are though 2 thriving copper hedges a few gardens along from me. Not the most experienced of gardeners but I cant seem to find anything similar or similar images of the leaves when I looked on internet.

any drainage ways that may be polluting the area.

No - nothing like that nearby

Do you get much sea spray? I understand that beeches are not fond of salt.

whilst we are not right on the coast, I think your're right -having a good look online - the stunted growth and burnt leaves does seem to be salt in air/soil. Question now is to heavily irrigate etc or give up and plant something salt tolerant?

Heavy irrigation won't really help beech. They love a good drink (huh, don't a few of us?), but they want a freely drained site. The salt air is a possibility, which is why I asked your location the first time. If you have to draw the line under beech, then below are a few suitable subjects, in order of height, tallest/largest first.

Crataegus (hawthorn)
Ilex (holly), both I. alterclerensis and I. aquifolium
Prunus spinosa (blackthorn)
Laurus nobilis (bay)
Pittosporum cvs.
Viburnum tinus
Elaeagnus, both E. x ebbingei and E. pungens
Garrya elliptica
Griselinia
Ulex (gorse)

Bear in mind that pittosporum, garrya, bay, and griselinia, although very suitable, may object to the extremes of cold likely on the east coast!