Charged for something I didn't get confirmation of

I tried to order Nandos from adderly str in cape Town. Just after the payment was processed (and received as I've gotten confirmation from my bank the payment was successful) the site 'crashed' and I wasn't able to see whether or not the order has been processed. I tried calling Mr D right away to confirm if it's been ordered or not to no avail and only option of contact was via email. I then called nandos to see if they received an order from me all this within the time of placing the order to calling Mr d. Nandos confirmed that the driver was already there to pick up my order. (In all my orders I ask that the driver call me as my work doesn't allow deliveries inside any longer.) I waited and waited and nothing was delivered. Eventually at 5pm I emailed stating that the payment went off but I could not see whether the order had been processed as I haven't received an email confirmation or an order number or that delivery was attempted. I then received an email stating the driver attempted delivery but I wasn't present therefore I'm liable. So now tell me how the flip am I liable if I tried to get into contact with the relevant parties. The driver didn't even attempt to call me as I've asked. The order took place 3 December 2020, it is now 7 December 2020 without any feedback from Mr d as to what had happened and will be done regarding the above. In my order history the order doesn't show aswell. I'm disappointed in the service as the delivery of food happens in real time and one should be able to get hold of them and not be asked to email and only receive automated emails.