Hello newisie
In your case of the ceilings being damaged, they aren’t part of an owner’s property, but form part of common property. So the Owners Corporation is responsible for repairing them, they must maintain Common Property under Section 62 of the Strata Schemes Management Act. (provided you are in NSW)
Your Owners Corporation should have required the window company to have had adequate insurance cover prior to engaging them for this work, and taken note of the policy details. Since you maintain the damage to ceilings was caused by them an insurance claim should be lodged against the window company and their insurer for the cost of reinstatement of the ceilings to their pre-works condition.