Am I allowed to put a sign up in my window displaying how I am not satisfied with my home builder?

We recently purchased a new home. When we purchased our home we were told we were being sold a strong, durable hardwood engineered floor and in turn received the complete opposite. It was a significant upgrade and the floor has not performed up to what they thought. The person who sold us the floor has since admitted they nothing of the product so we decided it only fair they do something about it. It has been downhill ever since...poor customer service...lousy communication and so on and so forth. We feel we have no other choice to get there attention on how serious we are and are wondering if anyone knows if there are any legal implications we could face by putting up the sign or notifying the media. We don't want to give up as they need to learn their lesson but don't have lots of money and don't where to turn to get legal advice....Thanks!