MultiChoice rewards are rather a ****

I am disappointed with MultiChoice. On the 15th of March I received an email informing me that I have been awarded with free Disney Plus for 3 months from 15 March - 15 June and informed to log in using my cellphone number. At first I was able to login, then a week later I couldn’t log in, I used Twitter to report and was given a reference INC-***, but now suddenly on my statement I owe DStv an extra R89 which is annotated as Disney plus subscription. How did we move from a free 3months reward to paying? What was the logic behind sending me an email if the communication of the award was false?