Appauling service - WARNING!!!

Based on persistent advise from the sales staff in store, I splashed out and purchased a Tempur 'Cloud' memory foam mattress at close on £1500. I run hot and specifically said I had heard memory foam didn't breathe well and was hot to sleep on. Was told this was rubbish and it was top of the range and breathable unlike other inferior memory foam brands.
I also queried the softness and was told a new mattress would be harder than that in store which I tried - it could take 6 months to soften.
I now have a mattress that is way too hot and way too soft. I've been told I can swap it out given their 40 Sleep exchange policy, at a cost of 10% of the value of the mattress, plus delivery, PLUS the real kicker - whatever replacement I choose I WILL NOT get a refund of the difference in price. Bensons have confirmed this is not in their Terms and Conditions however they will enforce it - seems illegal to me
All in all a total waste of £1500 and a dreadful customer experience. Be warned, this retailer is bordering on fraudulent. I cannot caution against them enough.
DO NOT BUY from them!!!