Indian postal department
Registerd item being not yet delivered to the delivary address

I have send my certificates from my college in Andra Pradesh [Anandhpur P.O] to Canada by Registered post [ RR 630616092IN] on June 17th. However till now its not being delivered at the mentioned delivary address. When i contacted the Post office to know the way for tracking the item they told me that they were helpless. If this is the case why should we prefer a 'Registered Post ' in india.