Those trees are all yours

So, to set the scene, our house is on the corner. Neighbor A parallel to us, Neighbor B behind us. We’ve lived here since 2015.

When the neighborhood was built, there were rows of trees, not native to the area, planted between the houses. Lovely idea, lousy execution. The trees got leggy, overgrown, and became a serious hazard. Our chain link fence looked bad, and a couple of times we were just lucky nothing was damaged. Neighbor A had quite a few dents from falling limbs as well. Last spring, after a particularly big limb narrowly missed wiping out the roof, we took our trees down. We had trees on two sides — between us and neighbor A, and another row between us and neighbor B. Between was something of an aisle(?)). Anyway, after we took down our 20 trees, neighbor A also took down their 10 trees.

Now, onto neighbor B, who insists that their trees are on our plot, and at first, wanted us to pay to take them down. When we refused, because no, they’re on B’s property, she offered to “split the cost.” Still no. Their trees are now hanging on by a thread. B is still insisting the trees are our responsibility. Yesterday, they offered to show me where the property marker was. It’s clearly been moved, because if that’s our back property line, then not only the trees, but B’s fence, HVAC unit, and shed are also all on our property. Short of paying for a surveyor (around $1000 where we are), is there anything I can do? I mean, I’m not giving in, but damn.