Perhaps you are not watering nearly enough?
When I transplant something like this, I water it every second or third day for a couple of weeks. I water enough to make sure the entire root ball gets water. I never let a new transplant approach dryness.
After a couple of weeks, the new plant is starting to get established in its new spot. I start to cut back on watering frequency, not the amount. I cut back to maybe twice a week for a bit then maybe twice after ten days or so. Each time I really give it a really good drink. After 2-3 months I kind of figure it has made it. I water much less frequently but still be alert to very dry periods weather wise. You have to safe guard against overly warm temperatures that increase the drying rate.
Without images, I suspect you are not watering often enough or applying enough water.
Good luck.
