Had a new deck put in using Monarch composite decking. In a couple of years it has cracked, swollen and constantly,gets mildew spots in a bright sunny area--in general it looks horrible. Complained to manufacturer.

Six months later they finally sent a rep who refused to accept any blame for the condition and reluctantly sent the local distributor 11 new boards. The shade is very different from the original color. The distributor no longer will carry the Monarch product. What recourse do I have to get Monarch to back their product and replace the entire deck and pay for the labor. The product has a 20 year guarantee.
How do I get them to honor that guarantee, since the product is obviously inferior.

Monarch decking is a Royal Pian