I have had the same problems with my Wisconsin birds the past two years. Lots of hills and valleys, thick woods.
I could get MAYBE one gobble in the dark, but after that, nothing regardless of my locator calls ect.. I got lucky on Friday after VERY aggressive calling. L0UD cutting and yelps, higher pitched box call worked better than slate or diaphram (my single reed worked better than double or triple). I got two to sound off, but not until 9:00 a.m. I worked those guys hard. They were with hens but kept moving my direction. Their gobbles stirred up two other toms that were much closer, but never answered any of my calls. One of those two came in from behind and presented a shot.
Try the aggressive calling, it might get them to sound off when the soft stuff doesn't. I it can't hurt to try and the next day you can go back to soft calling.