Answer: It's difficult to make a recommendation without having more information. If the central leader was broken off, the tree will eventually grow two or more branches at the site of the injury. If you do nothing at all, your tree will have a "V" shape as it matures, which can lead to breakage during wind storms. If you prune one of the emerging shoots off, the remaining one will become the new central leader and aside from a little crookedness, the tree should be fine. If only a few branches were broken within the canopy, you can prune them off cleanly and the tree should grow new branches to help the canopy fill out. I think it's reasonable to request a replacement from the landscaper. Best wishes with your new landscape!
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