Payback.in — Points not credited despite vendor (carzonrent) processed the refund

Website:

www.payback.in/home.html

I've redeemed the payback points at carzonrent last year but carzonrent didn't provide the service and they promised to refund the amount and payback points.

I've been following up with carzonrent for refunding of the points but due to their slow process, they replied me now that the refund is processed. But payback team is not accepting as it reached over 60 days.

despite vendor agreed but payback is not crediting the points.