Vodacom are ******s

I have a contract with Vodacom that I pay R325 every month. My problem with them is that I can't see the numbers when there's an incoming call it appears as UNKNOWN. So I called them to check in with the problem they advised me to pay R10 extra in order for me to see who's calling me. They further continued to tell me that they can't do otherwise because the sales man that assisted me was suppose to inform me which he failed. I am very disappointed in Vodacom because all Vodacom Prepaid customers can see the caller ID of incoming calls whilst we Contract customers must pay a fee for caller ID to me this is a ****************.