How get an VAT refund with an Apple Online Order ?

I was referring about an order made online on the Apple Store France. Got the delivery on the 18th. Got back to the UK, this morning. Wrote them (vat.refunds@apple.com)and it didn’t work. Vat.refunds told me, that I needed a pablo form. Didn’t had one as I told them it was about an online order. Then, after asking where to get the form or to whom. Told me … you have to act within 3 days following the delivery. Today, is day 4th. They said that they can’t help me despite providing them with : id, apple online order receipt, eurostar ticket, proof of residency, global blue card. I want to know more about those 3 days ? Where can I find more about the legislation ? Where to go to get answer as Vat refund has Chat bot answers and is keeping repeating the same thing without giving me any reason. Apple Care Support doesn’t know anything it. And when I went in Paris asking the info in the brik and mortar apple store. They gave me the mail (same as yours) with the list that I needed to provide. I did that but now, I want to understand the reason behind my rejection etc. Thanks for you help with this matter. Really much appreciated !