Shoprite Money market : I want a refund.....

Shoprite money market has been the worst, I opens a chat on their platform at 8 am till now no response. I need them to give me my refund for the voucher I purchased but I can not use. Do you know how embarrassing it s to be standing at a till wanting to make payment but their system is not allowing it. I am simply asking for a refund for the money I spent getting the voucher!!!! Horrible customer service