Refund never arrived

I bought a 24-inch m3 Mac on March 16 at the Apple store Nave de Vero(Italy). Having a company I paid with the relative card and after giving the VAT number data I returned home, after a few hours I received an email from Apple saying that the invoice would not arrive due to a data error, the next day I went back to the Apple Store (since I bought it the Mac is still packed) I am told that to change the data it would take a new invoice and, consequently, a new payment, they ask me if I had the Mac with me and after having said that I had left it at home I was told not to worry, that they would take the data of a Mac not yet sold and that after paying again I would receive the refund of the first payment within 1/2 days (2 days, 2 transactions of +2000€). I bought from a store because I was in Mestre, but living in Abruzzo and it is difficult for me to go to Veneto(500km). In almost a month, there is no trace of the refund, has anyone had a similar experience or can you advise me how to solve this problem in a civilised way?