Reliance Digital — i was received a coupon (invalid)

I've just received a reliance digital coupon code after i made a purchase on jioapp, but the code is invaild according to reliancedigital.in website..

I have also tried on lower priced products which are below price, but the problem seems to be still there, i think the given the coupon code is invalid from the start, i haven't used it yet, you can check in your backend there will be no entry of redeem of the coupon.
Why it is