What's the definition of insanity? Doing the same thing over and over again, hoping for a different result.
To whit:
The logs aren't working.
We had an ATV problem on our hunting club land years ago. We stopped it by putting up a couple (maybe 3) steel fence posts and stringing barbed wire between them across the ATV trail. Problem solved.
I'd put up a couple fence posts across the trails, link them with barbed wire - make sure there are several strands between them so someone can't say you tried to decapitate them - and then install steel "No Trespassing" signs on the fence posts with 5/16" u-bolts. They can try to defeat this or go around them, but it will then take either work or damage. Something that you should be able to clearly document via "before/after" pics. Trespassing may be one thing to the local gendarmes, but property destruction should get their attention.
If you OP are serious about keeping people off your land, then you need to get serious.
That means, call the Law when you are trespassed - every time.
Tell them you will sign a complaint - every time.
Tell them you want them prosecuted - every time.
You need to make clear to the local LEO's you want this resolved and that you're willing to follow up. After a couple examples, the word should get out. As it is, you're doing the opposite of what's going to work in the long term - no offense.
Good luck!