Avoiding to Remove Fallen Tree

We are not the owners of our property, all our concerns and problems are supposed to be directed to the real estate agent of the owners (written in our contract).

Recently a branch of a tree has fallen into our backyard from our neighbor. Nothing was damaged and no one was hurt. We called the real estate agent and informed him of the matter. He said that he will go talk to the neighbors and deal with the situation.

...It's been a month and nothing has happened. The agent said that they will remove it this Labor Day weekend, no one came. When we called the agent, he gave us the number to call the neighbors. I was confused since it was his responsibility to take care of our problems. My husband decided to call since the tree was decomposing in our backyard and would be a pain to clean up. No one answered after several calls, even when they were home( their light was on and we could hear them talking).

What do we do in this situation? Can we take legal action or at least threaten to? Who's responsibility is it to take care of the fallen branch?

A neighbor once dumped a double car seat in my front yard. I asked what he intended with that, he said he was waiting until he had time to take it to a trash-collection. I told him in that case he should keep it in his home until he has time to take it there, since people can file a complaint against me for making the neighborhood look bad, and: legally, as soon as any trash is in my yard, it is my responsibility to see to it, regardless how it got there. So maybe you should call the department in your community that can tell you whether this is also the case in your area, that might explain why the real estate agent feels they can get away with doing it this way.