Someone Says I Won a Prize I Never Entered
If you did not enter, you did not win. There is no mechanism by which a company draws a name from outside its own entry list, because the rules that bind it define the entry pool.
What the message is for
It exists to get a payment or a set of details out of you. The prize is the hook, the fee is the point, and the reason it is framed as a windfall is that people who believe they are ahead check things less carefully.
The tell, every time
It arrives at a request for money, card details or a gift card code, framed as tax, shipping, insurance or a processing fee. In the United States prize tax is settled with the IRS at filing, never paid to a company, and a legitimate company deducts nothing before sending a prize.
What to do
Stop contact, send nothing, and do not reply even to decline, since a reply confirms the address is live. Report it to the FTC at reportfraud.ftc.gov and your state attorney general. If money has already moved, contact your bank immediately, because some transfers can be recalled within a short window.