All credit reference agencies have the right to charge you to obtain a credit report from them. The service you are referring to is Creditexpert and there is actually a 30 day free trial during which you can cancel the subscription and not pay a penny to look at the report. It is £6.99 each month thereafter until you cancel.

Alternatively you can obtain a paper copy of your report from Experian for £2. If you still don't wish to pay this fee you can get a copy of a free credit report from your local Citizens Advice Bureau.