Amazon.in - Amazon is not ready to deliver smartphone for which I already paid

I had ordered for a phone google pixel * xl on **th May and paid ***** with EMI option through credit card. In the Amazon app, it has shown that the item is already dispatched and will be delivered on ** to ** May. But the tracking Id given was wrong. I called customer care to ask where is my order. They told me to wait for ** to ** hours. Now I got an email like that order is cancelled and refund will be done. I had booked that phone when there was an offer. Now it is out of stock. I waited so long and already paid for it. They gave a reason through an email for cancellation is from the customer side. But I didn't ask for a refund or cancellation. I called them numerous times to deliver the product and requested. Again they are telling me they can't deliver it. What's wrong with them I don't know. I already paid for that item and they gave information that the item will be delivered on the prescribed date. But now they are refusing to deliver it. This is really wrong and should take strict action towards them.