Complaining about every number is private when they call me

I have a contract phone with Vodacom. I called them complaining that I have a problem when people call my number it says private number for all the numbers calling me. When I called and complained about it they told me that I need to pay extra so that they can change that. When one buys a Sim card it already has everything ready and the numbers reflect on the screen doesn't say private for all the numbers. Is it my fault that they made my network day private for everything. Its irritating indeed