Hi Gregg,
I've found Neem to work well against critters, but if you suspect they're in the potting mix, I'd soak the pot in a more concentrated Neem solution than you'd typcially spray 5-10x moreso. Then spray the leaves, and do so one or two more times in intervals of 3-4 days to ensure you catch any hatching critters.
That should snap things around.
Julie