This might explain why you cannot use the HOLIDAY12 code:
PROMOTIONS TERMS AND CONDITIONS
Promotions are: Sales, Deals, Kits, Fantasy Baskets, Coupons and Discount Codes.We may introduce other price-reducing incentives intermittently, which will also fall under these terms and conditions.
Only one promotion can be applied to each product purchased from the website. For example: if you have a coupon discount code applied to a product and you consider purchasing that product in a deal or a kit (with a bundle of several other eligible products for the discounted price that applies to the deal/bundle), then you must choose which promotion to apply. You can purchase the product by choosing the kit or you can purchase each product from the kit a la carte and then apply the coupon to the selected product only. Please select the most effective option for your purchases.
Sale items. No additional discounts can be applied to items already on sale.
Expiration date. All promotions have an expiration date and time. You must place your order before the expiration date / time. We do not guarantee promotions after the expiration date.