Legend home is the worst!

Legend home is the worst!
We have MOLD growing in our vents & neither Lone Star or Legend home want to do anything about it.
We have a whole Neightbor dealing with this issue (Evergreen Villas) in Houston, Tx.
We ve also tried contact them numerous times but of course. They get back to us These houses aren t old either. We bought our house late 2018.