Uber India — illegitimate method of refund

I was charged incorrect cancellation fee by uber from my paytm wallet. On complaint, they made a refund in uber credits, which are non-transferable and can only be used for uber. It compels me to ride uber again if i want my money. I requested them to make refund on the original payment method for which they are refusing without any explanation. How can anyone charge a customer in terms of real money and refund in abstract money?? Pathetic scam by uber...