How to claim back a down payment for a car I purchased and didn't pass RTA test?

Hi

This is related to a used car purchase. I have given an advance for a used car through the bank & the car failed in RTA passing. The seller says he will do repair & pass RTA.

I said I don't want the car and to return the advance. Now he is refusing to pay back the money.

How can I return back the money?

I have all Whatsapp chats with the seller.