PIN CODE OR PAIN CODE

I am staying in Neelkanth palms for the last 3 years and have been using the Pin Code 400607.
I have been receiving the snail mail without any problem.
Recently I had applied for my passport and had indicated the same Pin Code on the application as well. Though it was overdue and confirmed by the travel agent that it was despatched by the passport office, I was not in receipt and hence visited the post office near D-Mart to enquire the status.
I was in for a shock when they told me that our area pin code is 400610.
The pin code 400607 belongs to Sandoz, Kolshet post office and first it would go there and then would be redirected to D-Mart post office.
The folks at Sandoz post office were not happy to help me which resulted in a delay of about 3 working days.
Meanwhile I checked all my mail and found that I have been receiving mail with pin code 400601 as well.

So I have these 3 pin codes - 400601, 400607 and 400610.
What exactly is our pain code, oops pin code that would deliver the mail at the earliest?