I recently bought Jupiters Travels by Ted Simon, an awesome book about someone who ride a motorbike around the world for 4 years in the 1970s. It's a great book about travel. It was the first time I bought an ebook from the kindle store.
However when I downloaded the .azw file I found that it was DRMed. I don't want to financially support DRM. Under EU law (Directive 97/7/EC - Distance Selling Directive, incorporated into Irish law as S.I. 207 of 2001), I am entited to a refund within 7 days for any reason. However I have to buy from the USA amazon.com, not amazon.co.uk, so this might not apply.
Amazon, have very good customer service, and will provide you a full refund within 7 days, if you ask.
Just click on the 'Contact Us' button on the Help page, then fill in the asking for a refund. Or you can go direct to this Kindle refund help page.