1500 voucher missing

I received a message on my app that i recieved a R1500 voucher for meeting some criteria. i logged in and saw the voucher there to be redemed. I went back in now to redeem it after checking out and now the voucher has just disappeared. luckily i took a screenshot showing it was there but now it is gone. i tried using fnb secure chat, they keep transferring me to ebucks help desk and after that there is just no response. i spent more that an hour on there waiting for any response but there was just no response. can fnb and ebucks tell me what happened to my voucher? I cannot spend time on the phone while at work so i need to sort this out via email or secure chat