Very annoyed customer

I was about to place a new online order and as I clicked on the items I received a tfg rewards voucher worth R250 automatically added, as I tried to complete my order the voucher disappeared,i have spent 30 minutes on a call with tfg customer care trying to figure out how the tfg rewards voucher just disappeared, nobody was able to assist me in trying to figure it out, unfortunately I did not take a screenshot of the voucher and thats the reason I couldn't get help.. you guys speak to me as if im trying to rob you of a voucher worth R250 Very annoyed with your service.