Yes, but only if the raffle has not closed. Head back to the launch page and you should see a red button that says 'Cancel my Entry'. Click that and you’re now out of the draw. You will not be charged should you decide to withdraw from the raffle.
If you do win the raffle and decide to withdraw, that is not possible. Verified entries are binding. Once an entry is confirmed, it means that you agree to purchase the product should you win (as per the terms and conditions). Once a win is allocated to a successful raffle entrant the product is no longer available for other customers to buy.