My understanding with newly planted plants whether palms or otherwise they would need more stepped up watering at least for the first season of its growth as it acclimates in its new surroundings, especially if grown as container plants. I would have also considered the timing of buying them, would have done it in late Spring than in Fall, so the palm would have been more established by the time colder weather sets in, even if they are being grown indoors. Light levels are changing with the seasonal transition now and bursts of cold draft will truly harm new plants. South facing windows are perfect actually at this time, tropical plants love all the warmth and sun they can get.
But you did point out it has some insect issues. It could be adding to its troubles, pathogens are entering faster.
Chinese Wind Palm or a Dwarf Palmetto, I think would have been a better choice. I do not know if your establishment would be willing to change the type of Palm to grow there, knowing a lot of money has been used up already. That would be my suggestion though if you really want to have a tropical look there. Replace the soil, and get a more cold hardy palm.
