From Coolerbooks.com's Terms and Conditions
1. Goods supplied within the UK will normally be delivered within ten working days of acceptance of order.
2. Goods supplied outside the UK will normally be delivered within twenty working days of acceptance of order.
8 CANCELLATION AND RETURN
2. The Buyer shall inspect the Goods immediately upon receipt and shall notify the Seller by email to customer.services@Coolerbooks.com
within 7 days if the Goods are damaged or do not comply with any of the Contract. If the Buyer fails to do so the Buyer shall be deemed to have accepted the Goods.
3. Where a claim of defect or damage is made, the Goods shall be returned by the Buyer to the Seller within 28 days of delivery. The Buyer shall be entitled to a replacement or a full refund (including delivery costs) plus any return postal charges if the Goods are in fact defective.
I suspect they grabbed a set of standard business terms and didn't bother to think about what that meant for ebooks. Hey look--if the book is badly formatted, you can return it for a refund! However, they might take almost three weeks to allow you access to the books you buy from them.
I can't find a thing on their site mentioning DRM, or the need to install special software to get access to some of the books.