I have a Telewest phone package that includes no charge to 01 and 02 numbers (i.e. normal phone numbers). I do, however, have to pay for the 0870/0845 numbers that companies 'helpfully' use for call centres.
It annoys me that I have to wait in a queue to get through, and I have to pay for the call (note that I believe that the company takes a cut of the fee for this 'customer friendly' phone number).
Well - use http://www.saynoto0870.com/ to find the normal 01x/02x number.
For info, Telewest's 'normal' number is 0845 1420 000 - use 0117 907 6666 instead for free calls!