Frustrated and Cheated

So I sent my aunt R500 instant money this morning. She went to the atm to withdraw on main Street Johannesburg , then the machine said there's a technical error. She then tried another machine... Same error. Then after a while she went back to withdraw then the machine said the voucher was already used. I call standard bank and they say they still have to do their investigations. So I had to resend another R500, except this time I didn't use instant money. I used to be such an advocate for standard bank and have been using it since around 2009. I feel so inconvenienced and cheated. Now I have to wait for the outcome of their investigation.