The problem in the UK is that in 99% of cases the Registrant (The company you used) will not have informed the Registrar of your details. In most cases the Registrant records themselves as the owner of the domain. This is usually done so that they only have to remember one set of usernames and passwords for all their clients if changes and renewals needs to be processed.
As well as bankrupt Registrants we can also recover domains from Yell.com without the need to pay the £46+VAT they charge!