No credit note received after refund for cancelled online order with AliExpress

On 29/06/2025, I ordered something from a seller on AliExpress. After payment, the seller contacted me to say that there was something wrong with the price and asked for much more. I refused and it was agreed that AliExpress would issue a refund. The next day, I received the refund amount.
Because AliExpress sent me an invoice (with 0% vAT because it was sent from France), I would now in principle have to pay the vAT amount to the Belgian vAT authorities (because I am exempted from vAT) via a 629 declaration. AliExpress apparently does not send credit notes (despite repeated requests to both the seller and AliExpress). That is nonsense, of course. Then I have to pay VAT on a purchase that never happened. How can I resolve this?