When you planted it did you use someting like bone meal in the bottom of the hole to help prevent transplant shock?
When I planted my Japanese maple 2 years ago, in the spring, it was beautiful for a month and then all of the leaves suddenly fell off. I thought it had died. I am from parents who were in the nursery business and was I embarrased by the situation. I left the tree in the ground while I was exploring options for it's replacement. The following Spring I HAD LEAVES! ! ! !
If you had a professional plant the tree, contact them and get their opinion. If you planted the tree and it had been dug by a professional, I advise leaving the tree in until after next Spring. It just might surprise you. If it does not survive, you can deal with it then but unless you have planted it in a location or soil incompatable to it and it dies then I doubt you can do anything more at this point. Keep watering it at the drip line and see what happens in the spring.