Paying for caller ID

I've recently converted my prepaid nr to contract. I then discovered that when people call me, it shows as unknown. Apparently I got to pay a R150 to activate caller ID. I don't understand why contract sims have to pay so much for a feature that comes standard on prepaid sims. I've never even heard of other nnetworks charging for caller ID. If you guys want to make money, then why not just conceal the caller ID fee in the contract premium amount because now this is just absurd.I am truly starting to believe that Vodacom is the most expensive network in SA.