I would contact the shipper, tell them that plant was damaged in shipment. What do they suggest? They have to have a problem department for these kinds of things. I don't think you can do much to fix new growth stubs that are damaged. Plant might be fine with less foliage, but came damaged. Shipper should be helpful on answers.

oh! i have a replacement on the way but i'd hate to just throw the tree away.

Remove the broken stem cleanly. No flowers from it this year, but it will resprout nicely next year. It will likely become bushier than the others because of this "pruning", which might mean more flowers at a young age, or it might mean no flowers at all until it becomes strong enough to put buds on all those shoots :)

Plant it deeply to avoid forcing suckers from the root stock and help the plant to establish its own roots.

thank you. i have noticed signs of life from other parts of the plants and this, with your advice, gives me hope.