Have a look at this site
www.immobilise.comA service backed by the Met Police,Home Office,DTI amongst others.To register your Mobile Phone to help if you are a victim of Crime etc.
They give you an online option,or yes you have guessed or an 0870 number to ring if you want info.
On there website they say that calls to 0870 are charged at Local Rate.
You will also see that there advertising materials mention nothing about the cost of 0870 numbers.
In fact if you call the number all you get is a recorded announcement telling you the Numbers of the Customer Service Depts of the Mobile Operators to report your missing phone to.Most of the numbers given are NGN 0845/0870 so its a double rip off!!!!