I never surrendered my travellers card upon leaving Mexico.. am I in trouble?

I was never asked to surrender my travellers card.. or travellers permit thing upon leaving Mexico.. (it's a little slip that we all have to fill in when entering Mexico) according to some travellers guides it's supposed to be handed back as I leave the country. I'm worried because if they didnt process my departure, I might be still in Mexico in their system.. I left by air. Am i in trouble?