Standard is doing ***** and ripping people money

I went to one of the merchant to buy but their card machine had a network problem and kept on freezing and the transaction went through on my side. So they said they need the machine to print slip showing its approved which it never did, then decide to go and withdraw cash and pay cash. I was told if it went through they will be able to reverse it but to my surprise they said it never went through. I called Standard Bank to check on their side they said they can see the money but the merchant needs to send an email cancelling so I can get the funds realised back to me. Last we sent an email with the merchant asking them to realise the funds back to me since I paid cash, now I’m told the money bounced back to my account and statement changed doesn’t reflect that amount as go out. So what I asked them why did I have to write an email to them to realise the funds while they knew it was going to bounce back to my account and if it did how is it suppose to show on my account so I know it bounced back because ever since I never saw any money back in my account. Standard is doing ***** and ripping people money