Amazon - Refund not received

I returned a product on Amazon and did not get my refund till ** days of having returned the product. I might have called the customer care atleast ** times and each time they told me to wait it is being processed. Then I reached out to amazon through social media and there also they keep telling me the same thing. Now they keep telling that the refund has been processed contact your bank. So I asked them to give me the refund reference number. It's been * days and they haven't given me the number. I don't even feel like that the refund has been issued by the company.