If you received a special coupon from visiting www.AQ.com by spinning a wheel, you can only redeem this coupon once per account. If you mistakenly received a second coupon, you cannot redeem it to an account that has redeemed one previously.
If you already received the coupon but keep seeing the wheel, this would only occur if you have cleared your browser's cookies. So if you cleared your cookies or are using a different browser, the wheel would not know you already received a coupon.