Ok, I'd say back the rifat off of light for a bit. They do like full light ultimately, but you need to re-acclimate it after arrival, and mail time is hard on them.
The instructions I got with mine were: first day in a relatively dark room, 15 minute of light the next day, 30 minutes the third, and so on. Take time in getting it up to speed, and it should be ok. Also, the couple times I've changed the setting for the one I have, the older leaves yellow or brown, but the new ones will grow in healthy to replace those that are damaged.
Other than that, give it plenty of water and high humidity if that's possible, and keep an eye on it. If it gets worse, let us know. Good luck!