Tier 2 dependant BRP Card not issued

Hi there,
we have applied for Tier 2 dependant visa for my baby in end of January 2017 from India as he got the visa till mid of May 2017 and Main applicant visa is also valid till mid of May 2017.

As in the application was saying that need to collect the BRP card from Post office I went to post office to collect the BRP card.They were saying that they have not received that card and also was saying by looking at my baby passport, got the visa till mid of May 2017 on his passport in that case doesn't need BRP card for my baby. This is what I have been told by them

do I need to contact home office regarding this or they doesn't issue BRP card for short visa.

Please let me know
Thank you

BRP cards are not issued when a visa is for less than six months if applied from abroad. Childs visa is what is in the passport and expiry when yours does.