Contact Contact Gentex If you need to return a product you purchased online, have a warranty or damage issue for a product purchased online, or have questions about your online order, please click here. You can also contact Customer Service at 888-894-1755, Monday-Friday, 9am-5pm Eastern Time. Have questions on behalf of your department, agency, or organization? Looking to submit a Request for Quote? Fill out the form on this page and we’ll be in touch. Our Frequently Asked Questions page may help you prior to contacting us.