Ussd not working

Yesterday I bought Chicken mxd 5kg Goldi chicken that was on promotion, you buy the chocken and get R160 airtime. When I try top up the airtime I got an error that the promotion has ended and on the receipt it states that the ussd expires on the 10th of November 2021. I need this sorted asap as I bought this for a reason and need to make calls to my clients asap.