Instant Money call center waste of time and airtime - no answer after waiting for long periods for someone to pick up the call

I received an IM voucher, when I tried withdrawing from the ATM, an error occurred and the ATM said I should refer to the slip. The ATM provided no slip to advise what the issue was. I then went to a different ATM, entered the voucher number and pin. I got another error message that the voucher had already been used. I still had not received the money and the money was deducted from the senders account. I tried calling the standard bank instant money call center numerous times and after waisted time and airtime, I still could not get through. I don't know what else to do as I am not a standard bank account holder.