Charles and keith - Defective Handbag

This is in reference to a Handbag that was recently bought from Charles & Keith singapore by my friend on my request.

There is a manufacturing defect in the bag.

The buckle on one side of the handle is so flimsy that the strap is unable to hold its shape & hence bag slips.

Pls see the imagefor the reference.

I went to charles & keith ( Ambience Mall, Gurgaon) today. They acknowledged the defect in the bag.
I have been sending emaila on their email id, but no response.
I called multiple times on their phone number- but noone is picking up.
It is a waste of someone’s hard earned money.
I need a response, i have never see such pathetic servicw from a so called high profile brand.