Company Check includes over 100 million records on limited companies and sole traders across Europe.
If you have a complaint about a company and are unable to reach the business to discuss this, try one of the following organisations for advice:
Consumer Direct http://www.consumerdirect.gov.uk/
Get Safe Online http://www.getsafeonline.org/
Office of Fair Trading: http://www.oft.gov.uk/
Citizens Advice Bureau: http://www.citizensadvice.org.uk/
Financial Services Authority: http://www.fsa.gov.uk/
You could also try contacting them on social sites like Facebook and Twitter.