Kalyan Jewellers — Gold card expired without any prior intimation

Address: Gurgaon, Haryana, 122017

I have purchased jewellery of around 80 thousand rupees and i was issued a gold card which can be used as a discount/cashback for the next purchase.
In gold card the amount is 800rs. And when i wanted to purchase the gold with this card in new delhi branch, they rejected it to accept this gold card, as they claimed that, card is expired.

I asked them, did you inform me that this points/discount 1% would be expired after few months/days???
Is it written on gold card issued to me??? (No where i can see that clause)
Did you written/stated somewhere on the bill??? (No where they have stated)
Did you informed me via mobile number that your points/cash going to be expired within so and so months/days??? (Didnt receive any message)

Then why are you not accepting my gold card points???

Literally they are cheating the people/customers...
Kindly do the needful asap.