How do i contact one step diagnostic customer service? Our Customer Service Department can be reached at (713) 461-7272 or email [email protected]. When calling, please have the patient’s name, date of birth, or an account number available. Thank you again for choosing One Step Diagnostic for your health care needs.How do i contact a one step retail customer? Already a One Step Retail client? Getting help is as easy as dialing 1 (800) 266-4915 or sending us an email at [email protected] Access One Step’s Self Service Client Portal where you can create support tickets, track your ticket, research past ticket history, view an open project, and more.Who is oneone step up? One Step Up is a wholesale manufacturer which owns and licenses a portfolio of National and International lifestyle brands in Ladies, Mens and Kids active wear, athleisure and casual sportswear.How do i contact onestepgps? Someone from OneStepGPS will contact you shortly. One Step GPS service specialists are available to help you with any and all questions you may have regarding your GPS tracker, Fleet tracking platform & apps and anything else related to your services with us. Specialists are available via phone, chat or by email.