Smytten — After 3 years of ordering from them, suddenly they deny my order , saying the pincode is not serviceable

I have been a regular customer of smytten for more than 2 years. I had purchased 100s of trial and shop orders from them.

Even though i had so much of problems in many orders from them, still i thought things will be alright and issues happening only with certain brands.

On my last trial to place an order, the system is rejecting my order saying, "the pincode mentioned is not serviceable"

!?!

How is that possible, when they could deliver for almost 2 years and suddenly they could not service my area.
How can such decisions been taken completely from their side, without even informing a customer concerned.

My INR5, 000 is with them in the form of Smytten Cash, but they forbidden myself to utilise my rightful reward and place my shop order.