Coil overs can be a little noisy in general, and the CX's seem to be in the lower end of the price range at what looks to be around $700. That being said, honestly have no clue about their quality and not knocking them just cause they seem to be a bargain compared to Megans, BC, Penske, DSE, etc.
So - what mods are on your Ride? Did the noise only become apparent after installation? Did you set the preload @ hand tight + 5mm off the car before installation, or unload the suspension and check the preload? When the car is unloaded, can you rotate the spring coils? Are you SURE all required hardware was installed from the old struts? Did you drill a clearance hole in your trunk sufficient to clear the rear adjuster extensions (the top of the strut coupling WILL hit the floor pan). The more info about your ride the better.
https://www.nationalgmparts.com/auto...omponents-scat
https://www.nationalgmparts.com/auto...omponents-scat