Canasta flawed

This game has a major flaw, it allows the computer to pick up a frozen deck when it has a canasta on the card. I hold the 3 remaining cards on the canasta and the computer picks it up? You must have 4 natural cards to make a canasta and I have 3 of them. So there is no way for it to have a pair to pick up the deck. Very irritating!

TLPD8772 about Card Shark Collection™, v8.0.3