Dogwoods as beautiful as they are in Spring are prone to many diseases. Dogwood anthracnose is a fungal disease what can prove fatal to the tree if left untreated. The maple could also be infected with the same disease. You might consider contacting the company that planted the trees and discuss with them a plan. A Certified Arborist in your area might offer a treatment plan that could be worth while. Below is additional information from the Extension network on IMP regarding Dogwoods. http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG12_IPM_Series_Dogwood.pdf

The vendor wouldn’t take care of the bushes that he planted that died right away so I’m sure won’t come back now 3 years later. The only arborist I have been able to find says they won’t deal with trees this small. Any suggestions if finding a qualified arborist? 

The website I have listed below will help you find a Certified Arborist. The International Society of Arboriculture https://www.treesaregood.org Additionally the Ottawa County Conservation District could also be a good reference for you as well