Pond Megastore review: I did as they wrote in instructions, but my lily was dead

I bought flowers from the company Pond Megastore. The process and delivery was ease and fast process. As well as the seller sent me the instructions of how to overwinter the water lily. I did everything as it was written in the instructions, but the water lily was dead after a winter. When I contacted the customer services, they refused to send another and told me that it was only my mistake. I don’t agree with them.