Jaw vs. Virgin Media

I am prepared to be proved wrong here but I would happily bet £20 that the 0845 number is pointing at a network based ACD/IVR, so it does not have an underlying geographic number, therefore say no to 0870 would be useless in this situation.

But if you can get a "regular" phone number instead of the 0845 number then you can use your mobile talk plan minutes which often don't include these sorts of service numbers. Obviously it all depends on circumstance :)