Empty box received from Myntra.com, no support

I ordered a ring from the brand talisman from myntra.com on 23rd feb2020 and received the delivery on 27th Feb 2020. The package was completely intact from outside but when I opened the package, the box inside was tempered with and the ring was missing. So, I immediately called the customer care up and filed a complaint and they assured me that they will resolve my issue by March 2, 2020. On March 3rd, 2020 I received a message that my claim has been declined and they refuse to give any valid reason for the same. I have been shopping from Myntra for so many years and never expected such a thing.