Found this
http://www.bt.com/premiumrates/Text from the above link
If you have received a BT telephone bill with premium rate calls that you do not recognise, the Independent Committee for the Supervision of Standards of Telephone Information Services, (ICSTIS), have a web site that can be accessed on
www.icstis.org.uk . This will also help you to check the most commonly queried premium rate (090) numbers. ICSTIS is the premium rate services 'watchdog' and regulates the content and promotion of services. . This web site provides details of those Internet Dialler services under investigation, usually with the contact details of the company that operates the service. Not all 090 numbers are internet dialler related. The vast majority provide access to information, entertainment or TV games services.
If you wish to dispute a particular premium rate call charge, please contact BT on 150 or 0800 800 150, (a free call from BT fixed lines), where your call will be handled by our specialist team. In the event that we believe that the charge is a result of an errant dialler, we will still ask you to pay the BT bill in full, however, BT will allow some extra time for payment to be made. We recommend that you check the ICSTIS web site to see whether the Internet Dialler service is under investigation. Where no such investigation is underway, we recommend that you register your enquiry with ICSTIS using the online facility on
www.icstis.org.uk. ICSTIS do operate a free helpline for customers who have complaints about the content and promotion of premium rate services. The freefone number for ICSTIS is 0800 500 212 and operates 09:00 to 16:00 Monday to Friday. This number gets very busy so using the online service is possibly the best option.