DSTV Reward invalid, DSTV is not helping a month later

I won a R250 Wollworths voucher from DSTV Rewards. The Voucher was sent to my cell number on 21 Februray 2021. On the same day I went to the store and I was informed that the Voucher was invalid. On 22 March I sent a Direct message to the DSTV twitter account and until today, 19 March I have been promised that the query has been escalated and that this would be resolved. I have reminded them almost everyday. I always get the same response. We apologize for the delay. It is almost a month since I was embarrased and felt like I had forged this voucher in front of people and DSTV is not doing anything to rectify this.