Just purchased a Fatsia Japonica & after 2 days itlooks as if it is dying

where abouts is it planted? how often have you been watering it?

x x x

Water it but don't drown it and put it in the shade and out of droughts, unless you have already planted it, then I would move it to a semi shaded moist area and give some liquid feed.

Water? Though you don't say what it looks like - is it just drooping? If so, its either too wet if there's no drainage, or not wet enough.

If you only bought the plant two days ago then go back to the supplier and complain. I don't think that you can significantly over or underwater a plant in that short space of time.

Did you soak the root ball before planting it. The soil has to be mulchy and moist and the plant prefers shade. I would give it a bit longer to recover. Most plants dislike being disturbed, but the Fatsia Japonica is a forgiving plant and should recover. Take some pictures, keep it moist, not soaked and it should be fine. If the leaves start turning yellow, that's when I would take it back to the shop.