Disappointed

Bought a gift voucher on the 24.12.2022 from the Gugulethu Foschini store. So I realised it's missing now but I still have a receipt i call their customer care line was told a form needs to be filled in at the branch for them to investigate they'll have to check first if it was used or not emidiately I rush to the store for the store manager to tell me there is nothing they can do. Though I explain what was said at their contact center but still there is "nothing we can do about it" can you check or cancel it because it's a card it can be traced with the reciet ? "No there is nothing we can do" that's the answer from the manager. Branch number 000415, card number (last 4 digits) 6000, Auth Code: 503246, Seq no: 111473, ESC: 121, RNR: ***