[moonrab]

A Sg Talker here, who claims to be a patient and considerate driver, advocates dismantling the gantry if no one answers the intercom when the barrier doesn't go up. He doesn't think that vandalism or damage to property is wrong.

I was once caught up in same situation. It was in a Shopping mall, whereby the gantry is at the narrow slope slipway leading towards building exit road. 
Many cars were behind me too..🤣

Normally the intercom button will call up the security guard. 
Just wait for them to manually open gantry. 

If really no response, park car aside and walk to security guard post to seek for help. Commonsense. 

No building management will ignore gantry failure, because there are many cars going in and out of the carpark. Not possible to cover up the problem.