No proof of payment available for online transactions

I moved from Investec to Discovery Bank (big mistake). I cant get a proof of payment for an online purchase. The merchant understandably does not want to process my order for the payment I made and requested I send them a proof of payment. I phoned Discovery Bank and they told me I cant get proof of payments for online purchases, only EFTs. With Investec I used to be ably to click on any transaction and get the proof of payment. The lady told me they can draft me one, but it will take 48hours. I urgently needed make transaction to be processed on the merchant's side and now I have to wait 48hours for somethings which used to take me 5 seconds. Usually after I have been on a phone call, Discovery ask me to rate the level of service, when I asked the lady to put me through, she dropped the call