Well, this method is quite known, but not this new case opening page, that now, is accepting paypal.
As you can see, a few hours before i made this thread, i asked for some paypal refund, and they gave it to me almos instantly.
Storytime:
Yesterday i was at a friend house and decided to open some csgo cases since i had like 50$ on paypal, we opened the cases (actually got a ak-47 the empress 33$ worth in a 10$ case) and today, when i got to my house i said that the movements to the page where uknown to me and they gave me a refund.
It's quite easy, and you need to have really bad luck to lose the paypal case and dont make profit opening the cases.
Link & Method