Bad service

On the 30/06/2018 I bought prepaid electricity using my credit card. I didn't get the voucher number I received an sms saying my purchase was unsuccessful, my money will be paid back into my account. on the 2nd and 3rd of June i spent more than 1h:30m on the phone with FNB being send from pillar to post. I then bought another electricity now they saying they cant credit me they can retrieve the voucher. I don't need the voucher I need my money back into my account, to pay other stuff.