Transaction cleared but merchant saying they haven’t received payment

Hi, I could really do with some help here.

I paid for a takeaway on a card machine brought to my front door by the delivery driver. They had some issues with reception, but eventually payment went through and my Monzo balance decreased.

The delivery driver came back to my door ten minutes later to say that they didn’t receive payment and showed me the card machine report that didn’t have my paid amount on. They wanted payment again, but I declined as it had left my Monzo account. So they said tomorrow the transaction will probably charge back and then they’ll call again for payment.

The next day I checked my Monzo statement and the transaction is no longer pending and is appearing as a cleared payment. But sure enough, the restaurant calls and demands payment, which I’m hesitant to do as effectively I’d be two payments down.

They want me to call Monzo and ask them to refund the money to my card, so they can take a new payment from me.

I’m not keen on this idea and not sure Monzo will even do that. Any thoughts? I feel as though the issue is with them and not me…