Firstcry.com — Ordered 2 shirts received only 1

I have recently ordered 5 products all in the quantity of 2 from first cry . I have 9 out of 10 but have not received 1 tshirt. It was prepaid order . I raised complaint on firstcry through their app and the response which I got is that they have sent correct quantity. The weight which was written on parcel was 0.20 gm and they claim it was containing 2 tshirts but that's not possible. They are not listening and claiming same thing. I am one of the regular customer of firstcry as I have twin babies I always order for 2 quantity of same thing. This is the first time I am facing this issue. Pls do the needful