AFAIK while urgent repairs are certainly part of RTAs – allowing a tenant to do the repair to the LL’s property – I can’t seem to see where they are part of OC Acts.
I’m not sure a common property letter box lock would be classed as “urgent” anyway.
In all my stratas, there is an after hours number to call for emergencies. And they arrange any genuine urgent/emergency repairs.
I sure hope they would accept a call from a tenant!
IMO this situation is both the Strata Manager and the LL’s agent behaving badly.