Grofers — Blinkist 50% off for first user is fake

Address:

Bangalore

Blinkit claim for 50 % off for first user but they are internally making user as existing user and saying no offer.
I am first user of grofer/blinkit so coupon worked for me but I did not got delivery in 18 min and after 24 hr my order got cancelled without any reason and when I reordered it says I am existing customer, this is same happen with many of my friends. I think it is their strategy to fool customers and increase their database with no of people. But I made a mistake ordering from blinkit which says 18 min delivery but it never happen instead I would have ordered from swiggy and i would have got same day delivery.