The best US Postal Service (USPS) – Los Angeles Division of Consumer Affairs customer support number with quickest path to a customer care executive or a technician. A phone number system with less hold time in comparison of other phone numbers call now for live support from your computer. US Postal Service customer service. Get in touch with USPS’s customer service department through the following phone numbers, email, social media and contact form. For more information about deliveries, tracking, claims and postage fees, please call the phone number listed above.