MTN? DSTV Festival

My granddaughter won R 1000.00 at the DSTV festival in Micthells plain at the MTN stall. This occurred on November 30, 2025. We went to two MTN stores, but nobody seemed to be able to assist us. Till today, she has not received her winnings. WE visited the stores in Promenade and Westgate Mall. I was given the number for MTN Momo ***, but this number just gives you the option to choose from. I really don't know who to contact anymore. My question why have a competition if you're not willing to pay the winnings