I don't know who you are paying rent to, but I think if this isn't covered by insurance, or repairs that the organization you're renting from, you probably have to bill your neighbor for the damages. Out of respect, you should inform your neighbor in a non-hostile way that their reconstructing has damaged your ceiling. Offer them to even come see it themselves as well and do add that you're not mad, but that you do want this fixed. If your neighbor can't do anything, then chances are, you're just gonna have to hire somebody to repair it, possibly contact your insurance company and see what deal you can strike with your neighbor assuming he/she is friendly and wants to help.