Is my Laceleaf Japanese Maple Dying. How do I save it?

I bought a healthy Crimson Queen Lace-leaf Japanese Maple 4 weeks ago. After about 2 weeks I noticed that the leaves started wilting/drying and curling. When I touched the leaves they just fall down. This tree gets a lot of direct strong sun for 4-5 hrs per day. The soil in my area is very clayish. I dug a little soil around the tree to see if tree is drowning or suffocating and I saw that there was pool of water around it. Looks like the soil in my area is not draining but retains all water. Would this property of soil drown the tree? Do I need to move it somewhere else. Is it enough if I remove the tree add a little soil under it to increase the height and replant it in same place ? I also tried to break some small branches and it looks like some are brittle and they easily snap. The bark looks green. Please advise on options. I don't want this beautiful tree to die. Is there a test to tell if it is alive.