I don't know if it is legal. But the same happend to me one year ago. For me pokerstars has the worst withdrawel time. I had been a member for a long time, i got some great hits so in total my withdrawel was about 3000€ on a 50€ deposit.
First like you i had to wait 48hours, when i made a withdrawal they asked me for additional verifikation. They used one week to verify me, Never send so many different document to same site, selfies with my passport, phone call with questions like "what slot you played last, what is the biggest win, what card you use for deposit. When my verifikation was done they cancel my withdrawel and asked me to do it again.
One week later i had my money, so in total over two weeks in total to get my money. They also had a strange withdrawel, some of the money showed like a cash back on my account (the deposit) and the remaining like a normal withdrawel.
You will get your money for sure, please don't gamble with your winnings