buy prepaid electricity and never receive my pin

If use my standard bank app to purchase prepaid electricity. For the past 3 purchases over a time span of 2 months I did not receive my pin. For every purchase I have to phone standard bank customer care during working Hours at my own expense to recover my prepaid electricity pin. I’ve almost spent R100’s worth of airtime holding on the line to resolve this issue. Not to mention the time I’m left with no power due to having to wait for operation ours. I cannot retrieve my pin on my app or on online banking which I find totally ridiculous. It also does not show when purchased. Every time I phone and query this I have to hear it’s a technical error. How long will this error persist till its resolved.???? I cannot count on standard bank services and its costing me money unnecessarily !!! I’m furious about this issue.