To file a complaint online, select the topic below "What's the reason for your inquiry?" on the USPS "Email us" page. File a complaint against a business with BBB, search for a business to file a complaint against, or find out the status of a complaint you submitted.File an Online Complaint. Postal Inspectors suggest that, before completing a business transaction, contact the Chamber of Commerce, Better Business. Travis lodged an administrative complaint with the Postal Service, which denied her claims and issued a right to sue letter. The Department of Consumer and Worker Protection (DCWP) will consider your complaint a tip. If you include your address, DCWP will mail you a complaint form. No hot water to wash hands. And if you have questions, fill out our Get a Quote Form to get connected to our sales team. Fiserv distinguishes itself in the merchant services industry as a direct processor with major credit card networks like Visa and MasterCard.