Refuse to pay Winnings

I been play for a long time at Gold Rush in the Vaal Mall Vanderbijlpark, Yesterday I was play for about 2 hour on a machine when is shows Jackpot Hit You Win Mystery Jackpot Level 1 ZAR 3,295,82.

I Call the manager, he came and confirm, but struggle to get the money loaded, after a long time he came back to me and told me it was a mistake on the machine and that it was was earlier the day on that machine and they cant pay me out, I took a picture of the screen for proof, but they will not pay. So that means they can tell me any winning is a glitch on the machine,