I bought a 4k screen here a year ago or so for 458...

I bought a 4k screen here a year ago or so for 458 euros the next day the price went up with just over 50 euros I suddenly get a message that I have to pay the difference if I had already paid it and it was confirmed.
She refused to send it until I had paid it or I had to cancel it and I still tried to negotiate because this would normally not be allowed for something that has already been paid and confirmed.
The last time I ever buy anything here.