Dstv false promotion to lure customers into buying

I received a message from Dstv on the 29th of may 2020 that if i rented a movie from box office the coming weekend i will get a guaranteed R100 pizza voucher. I rented the movie on the 31st of May 2020 on Sunday. I called dstv on the 3rd of june 2020 to get my voucher and i was told that they don't deal with promotions, i was then advised by an agent to take screen shots of the messages and send them to this email " faiq. ***" on the 3rd of june at about 10:30 to 11:00 in the morning ...i received no response up until i called again on the 11th june 2020 and i was told that my complaint was never recorded and we started from scratch with the agent and demanded a reference number which is ***_i221...i received no response yet again and i called on the 17 June 2020 and i was told straight up that dstv has no promotions. I then asked that why did they send a false promotion to lure me to rent a movie from box office and not give me what was promised. I'm very much unhappy with dstv and regardless of how many times I've called they have never even once gotten back to me. I only rented that movie because i was interested in the promotion and what it promised.