Sounds like you are an owner. If so, come down like a ton of bricks on the Executive Committee of your building before your building comes down on you. Tell them the Strata Manager is ignoring you and a terrible problem which is going to be terribly costly to fix if, indeed, it is a broken pipe which can cause the dreaded ‘concrete cancer’ sometimes more politely called ‘spalling’. This needs to be checked out pronto. Really!
If you are a tenant, come down like a ton of bricks on your agent or landlord.
Concrete cancer CAN be fixed more painlessly and efficiently by experienced, reputable operators who may not necessarily be ‘the cheapest quote’ but will do things properly, and keep the concrete silica dust under control.