New Cell C Black service confusing to use, bad explanation

Hi I received the following sms: Enjoy your Holiday gift on us! Rent or buy a movie from black and download or stream it for FREE. Download the GETblack app or visit www.black.co.za and choose your blockbuster now! Valid until 31/12/17. T&C's apply Now I've registered, downloaded the app. But I struggle to even get the free movie or anything else. When I try a movie, it takes me to a payment screen, to pay either with credit card or prepaid airtime balance. How do contract customers use this. If I use the credit card option, how will get the free movie or even the free trial. I've tried calling customer care, but I get no proper answer or help as I was repeatedly told to go to the channels, but that's not what the sms say? What's the point off all the data for the black service if I can't use it, I'm not even sure if I have 7 days trial or if it ran out. I'm confused with this.