WHY CAN I NOT USE MY GEMS 2 GET IN2 PARTIES HELP!!!! TYVM

WHY DOES IT ONLY TAKE PASSES 2 GET IN2 PARTIES. I DO NOT HAVE ENOUGH IN PASSES SO WHN I SAY NO 2 USING PASSES IT WON'T LET ME IN2 PARTIES EVEN THOUGH I HAVE ENOUGH GEMS 2 GET IN. HELP!!!!! TYVM