Jiomart - Return is not Accepting

Good Evening Team,
Could you please help me on the below request, number of times spoken to the customer service unable to get help from them.

I have planned to install Jio AirFiber to my house on **th September and I have gone through the Jio devices and found the JioExtender which is expensive and I thought that the performance will be very good so that I purchased in advance the JioExtender* Mesh Wi-Fi System (JioExtender JMB**) which is required for my house, On **th September installed the AirFiber to my house since then I am trying to connect JioExtender JMB** in Jio Home App and unable to configure the extender to my AirFiber router tried number of times and I have called number of times to internet customer care they haven't helped me and said engineer will visit but no one visited to configure the extender and he said I also don't know how to configure, finally I came to know that JioExtender JMB** is not compatible device to AirFiber and the compatible device is JioExtender JE****.
I would kindly request you to please help me and let me know how to return the device and how I will get the refund for it, so that I can buy the JioExtender JE**** which is compatible.
I am suffering without the internet downstairs, please take immediate action and respond to this email.
Thank you in advance
Many thanks
Kind regards
Veera