Airtel - Filthy Airtel Broadband Router

I ordered airtel xstream fiber on **th october and the connection was installed and activated on **th october and after one hour of installation the router stopped working and when I called the installation guy he checked and told me that the wifi router does not work anymore and should be replaced with a new one.
So I called the *** customer care and asked them to replace my router , even after multiple calls and requests my router is not replaced , and with grief Im writing this email , please replace my router.
Landline Number : ***********

Registered Mobile Number : **********
please replace my router with a new one as soon as possible.