Chat is available Monday through Friday from 8:00AM - 8:00 PM EST. U.S. Customers: For prompt service please call our MSC eCommerce Customer Care Team at 800-753-7970. International Customers: For prompt service please call our International Customer Care Team at 1-888-080-2048 (within the U.S.) or 001-248-200-4420 (outside the U.S.).