Illegal decoration, the property failed to solve the problem, which department should I find?

First of all, it is embarrassing for the property company to violate the rules, and the property company has no law enforcement power. The duty entrusted to enterprises by law is to "inform in advance, dissuade in the process and report afterwards", so the property has no obligation to stop and eliminate violations.

It is his important duty to find urban management for illegal decoration. If it infringes on the living safety of other owners and the property depreciates, you can sue him in court.