Neighbors Want To Sue Us Over A Retaining Wall - Nebraska, Usa

I would really appreciate advice on this as my neighbors told us yesterday morning that they are going to sue us over a retaining wall. Location: Nebraska, USA.

When my family originally moved into the home, we did not know there was a retaining wall on the fence line between us and our neighbors. The retaining wall is only visible in the neighbors' yard.

The neighbors have become upset, stating the retaining wall is in disrepair and it's our problem since the previous homeowners put in the retaining wall. Unfortunately, when we bought the home, we waived inspection so this retaining wall was never disclosed to us. We didn't even know it existed until the neighbors told us that they wanted us to fix it.

The neighbors wanted us to get a city surveyor out to identify property lines, and we were open to that until we learned that it cost almost $800 to do that. We figured that if the retaining wall is ours as the neighbors say then that would be a lot of money to add onto fixing the wall.

We told the neighbors this summer that we could fix the wall when we fixed the fence. The neighbors disagreed, stating that they wanted a new fence AND a new retaining wall in the fall. Also, they didn't want anyone in their yard. We said no the new fence since we cannot afford that, but that we could fix the wall and add a drainage layer in the fall.

Well, the neighbors did not seem to like that as now they are saying that they are going to sue us. They asked us if we received a cease and desist letter, which we did not. That also doesn't make much sense to me as they want us to fix the wall, but also cease and desist? They also said that they wanted to wait until the fall, but have changed their minds and want it fixed now.

Any advice? I feel like a doormat at this point.