1-voucher

I bought a 1-voucher from my banking app on Saturday evening when I tried to enter the voucher it showed duplicate along with a reference,yesterday I called and the lady I spoke to said that the rewards department is closed and she gave me a number to call.I called today and they transferred me to the voucher department I was on hold for 20minutes nobody picked up the other side and my query has not been resolved .I want my voucher or my funds refunded to my account!