Oh dear, I think that you've got problems.
The domain name CityDVD.co.uk is registered to an address (using a PO Box number) in Guernsey. The chance of that being the actual location of the company is negligible.
Indeed, the company goes out of its way to say "Your silly UK (and EU) rules don't apply to us, so tough sh!t, mate!". Of course they put it slightly differently but their statements amount to exactly that. Here's what they actually say:
Quote 1:
"We are not a UK based business, we have no connection with the UK whatsoever and we maintain a .co.uk domain name for the benefit of our UK customers who usually like to shop on a website that is priced in UK Pounds"
Quote 2:
" . . . if it truly does go pear-shaped then be aware that we are not constrained by the distance selling regulations of the UK and we are outside the remit of the Rome convention. Your consumer rights are affected by this . . . "
Source:
http://www.citydvd.co...d56614171331187747342
So you seem to be dealing with a company outside of the EU. The chances are that it's in the Far East, quite possibly in China. So, unless you know a Cantonese-speaking lawyer with expert knowledge of what limited consumer protection laws there might be in China, you're wasting your time trying to pursue any legal claim.
Sorry!
Chris