I have lots of raccoon's around here. They raise hell with the chickens but have never messed with the plants. Pheasants on the other hand seem to like to nest in them. You might try a bunch of rat traps not sure you would want to bait the traps it would just bring more of whatever is messing with you.
I've only had to deal with a hyper active dog running and crashing into my plants. Haven't battled the might raccoons yet. Have you tried installing a garden fence? Or maybe put a tarp or pan on the ground with a rag soaked in vinegar or some kind of repellant placed on the top.
What is happening to you already happened to me a few months ago. I am pretty sure they are skunks. They go for the bugs in the soil dieregarding your plants. I used to find them under a bunch of soil. I strongly advise you build a fence around them. Use chicken wire or meshed fencing. Saves the hassle of finding your plants dug up. I rigged up a fence with 3-4 poles around each plant and it has worked fine ever since. Good luck.