Charge for incoming calls caller ID

I took out a contract with Vodacom based on the feedback from other customers on how good the services and pricing is. Upon using my contract I realized that all my incoming calls were "unknown." At no point did the Vodacom agent advise me that the caller ID for incoming calls will need to be activated and is chargeable when i was taking out my contract. After doing some research I had to call Vodacom to activate the service. However this service is chargeable at R9.50pm for the duration of the contract, yet prepaid customers do not pay for this service. From a consumer perspective this is quiet unfair to the contract customers as we are paying way more that a prepaid customer. My previous service provider did not charge me for caller ID on incoming calls. Vodacom should seriously reevaluate their pricing structures because this is completely unfair to contract customers. Vodacom will not be my service provider of choice in future and friends and family will be advised of this accordingly.