Chips missing after a game?

[ImprovinNewbie]

i used a brand new set of custom chips in my game last night. i knew how many of each chip i had but at the end of the night 7 $25 chips were missing.

one guy called this morning saying he had 4 of them and that he was drunk and went south for his initial buy in. still 3 others are missing. im a little worried that they may get introduced in a future game... what can i do to protect myself...

the game is all pretty close friends and really no outsiders.... suggestions?