My question involves real estate located in the State of: Missouri

I have lived in the same residence for the last 30 years. In our backyard, our neighbors built a chain link fence all along their property lines (multiple neighbors did this, one long chain link fence). Everything is fine and dandy. We get a swimming pool installed and there is a retaining wall that is built to support this about 4-5 feet from the chain link fence. We purposefully didn't build this wall out to the property line so we could get back there and maintain it.

Last year, a new neighbor moves in and decides on his own that the property line actually extends all the way to our retaining wall. He asks if he can build there, we say no. 2 weeks later there is a fence post in concrete set right up against our wall. We tell him we did not give him permission to do that and he calls us a liar and said that we gave him permission. We hire a real estate attorney and get a survey done. The survey shows he is indeed on our property by the amount of space the old chain link fence was formerly located (the surveyor noted "possible encroachments where neighbors' property was located).

The attorney sends him a letter to cease and desist via certified mail which is apparently never collected by him. At this time money is getting low since we just paid for our daughters wedding so we could no longer afford to pay the retainer fees. Now that spring is around again, time to open the pool and we go back to look and there is now a fence built up against our wall.

Advice? Even though the survey shows the neighbor is on our property, can we go back there and tear it down? Or should we just take this thing to court?

Thanks in advance