BB Curve 8500 :: 8520 Hide Or Block Bb To Send Caller Id

i have just bought a bb 8520, and i cant find where to block the phone sending my id [telephone number] to who i am calling.i have called my carrier because this is a service that they have to add to the plan, but they told me that the only way is to dial #31# before every phone number thats an option, but unreal, beacuse for the 99% of times you choose the phone number from the contact list [or you should modify every phone to have the #31# before the number]i had a nokia before, and this option is easy configured through the options tab does anybody knows where to configure this option?