ya, this is a common problem for a top floor unit..Normally the office will have to repair it as it falls under common area..

did you report it in writing ? if not please do so and remind them that under the strata law they are responsible for the maintenance
and repair of the roof which falls under common area ..faced the same problem before but the office always take care of it..so no issue

if no action you can file a complaint with the COB