prepaid electricity hassle

I have been a Standard bank customer since I started my first job. Last night we bought pre-paid electricity and never received a voucher. This is not the first time this has happened. I have spent the bulk of today on hold with Autoserve, without actually speaking to anyone. There has to be a better way to do this? We are no longer able to check for the pin on either the mobile app or internet banking, so we are forced to phone and listen to the pre-recorded message. At this point, I think it might be time to change banks! The service has gone down the tubes the last couple of years!