Snapdeal.com — Product missing

I ordered "Milton helix 1000 pet water bottle, set of 2, 1 lit each, orange" for Rs.199/-. I have placed order on 13 dec 2022 & it delivered on 18 dec 2022. When I opened the package, I saw that only one water bottle is in it. I already payed Rs.199/- for set of 2. Then i applied for return/replacement. On next day delivery boy was reached my home & saying i can't take this package back because in his records "2 sets" he need to collect from us. When I said him " i have received only 1 item in place of 2 that's why I am returning this package" but he (delivery boy) saying you need to give me 2 items because their records showing that they delivered 2 items and he (delivery boy) rejected the pickup. And leaved from that (my home ). So now I want to ask that how i return 2 quantities if I got only one quantity in delivered package. So, i want to company solve this issue as soon as possible & also wants to konw whose fault in this. Take my seriously and solve this issue as soon as possible.
My mob. No. [protected]
Order I'd :- [protected]