Flipkart — Order not delivered and no help from customer support

Website:

www.flipkart.com

Order is showing in the Flipkart application as delivered.
But I have not received the order.
Checked with neighbours and security person but no luck.
When asked Flipkart customer support, they closed the issue saying that order delivered by sharing OTP.
Delivery person never called me and not shared any OTP.
Out for delivery msg is also not recieved.
I have called Flipkart support for 6-7 times but everytime they raise issue and close it next day saying that order delivered already.
I am not getting any help from Flipkart and I am very frustrated now.