Customer Service | Best Sliding Glass Door First-class service you can expect every step of the way How we apply customer service to your Sliding Folding Doors Cover Glass USA’s service goal is to provide incredible, professional and friendly customer service for our best rated sliding glass door system and large sliding windows. From initial contact to quoting, to post-installation support, our team of representatives is here to provide assistance throughout your entire experience working with us. Our Frameless Sliding Glass Door Systems are backed by our industry-leading 10-year Warranty. It is our goal to treat any and all requests or address any issue to come to a resolution as fast as possible. Most issues encountered are easily fixed. Feel free to call us at 1 (800) 317-2984 to talk to our Customer Service Team to see how we can be of better assistance. Please be sure to have either your Job # or the name of the contact person for the job, as we will need those details to pull up the information in our files. We look forward to speaking with you!