Imagine Marketing Private Limited - package not delivered

I have purchased the boat powerbank in august ****.It was stopped working after a month and i registered a replacement.The pickup was happened successfully. On nov** **** I received a mail saying that the product is delivered and they are closing the complaint ticket. But I did not receive the product. When I enquired with the courier people, they said it was misdelivered and to contact boat customer service to resolve the issue. I have been calling the boat service center to get the issue resolved. But every time when I call them they will say that the issue gets resolved in two days from two months. I lost hope in either courier partners or the manufacturer of the product.