Mrd is a ****

I got rewarded a R150 voucher and I decided to only use R77. 80. I though the remaing funds will be made available in my wallet unfortunately that was not the case. I called the call center and wasn't help at all. I was told that unfortunately there is nothing they can do, I have to forfeit my balance. I am really upset. I work hard to get this voucher and I couldn't even enjoy it. Useless app