Sports All Bet scam
They ring you up and tell you that you have a long forgotten betting account that was run by a third party that you used to have an account with, in this case Cybersportstab.
Lo and behold, now the balance is a touch over $50,000 !
All you have to do to get access to your account is pay them $2,500 to take care of the amount that was initially credited to your account by them so Cybersportstab could place some big trades for you. How generous they were.
They are supposedly based in Costa Rica and have a crappy website with no contact details. NO way you would want to trust them with your money.
Please do not fall for this one. Other people have been sucked in before in very similar schemes. You never get access to any account with lots of money. You always lose your own money and then there is nothing you can do about it.