Yeah, those coons know exactly when the corn is almost ready to pull and can wipe out a corn patch in a couple of nights.
It's happened to me before and I feel your pain.
The only solution I have found that works "most" of the time is to put up a four wire electric fence. I start the first wire at 3" off the ground then have the next 3" above that. Then 6" or so and the top wire at around 3 feet for deer etc.
I also put a live trap between every other row just in case they somehow get through the fence.
Don't bother with a cheap fence charger either, I tried one and they [coons] just went through it.
The fence charger I use now is supposed to charge 25 miles of fence and is rated at 2 joules.
It's a little on the expensive side and a little bit of work setting it up but believe me it is worth every penny to keep those pesky little rascals out. It even works for squirrels which can destroy a corn crop in short order.
Good luck!!!
