The United States Postal Service (USPS) is a government agency that provides shipping services. Shipping rates are determined by the type of service chosen to send or receive a package, the destination and the weight and size of the package. USPS offers an online service that allows customers to calculate domestic, business and international mail rates. Contact the USPS through email, phone or postal mail to explain the circumstances of the dispute and request clarification.

Contact your local post office that delivered the package. Go to the official site of the United States Postal Service (usps.com). Click “Locate a Post Office” at the top of the page. Enter your zip code and click “Search.” The next page will have a list of the local post offices in your area. Find the one that delivered the package and write down the phone number.

Call the post office and provide a postal worker with your name, the date you received the package and the tracking number of the package. Explain the cost of the shipping charge and your reason for disputing it.

Contact a United States Postal Service customer service representative, if the shipping charge dispute cannot be resolved at the local level. Go to the official USPS website (usps.com). Click “Customer Service” at the top of the page. Locate the contact information in the middle of the page.

Click "Send Us An Email" under the "Email Us" category to dispute the charges over email. Select "Problem" from the "Inquiry Type" drop-down menu. Click "Buying." Click "Prices and Fees," and choose "Domestic Mail Rates" or "International Mail Rates," depending on the type of charges you are disputing. Click "Continue" to fill in specifics regarding the shipping charges. Click "Continue" to fill out the "Contact Information" page and click "Continue" to send your complaint.

Call 800-275-8777 to speak with a customer service representative regarding the shipping charges or write a letter explaining your dispute and send it to United States Postal Service, Office of the Consumer Advocate; 475 L’enfant Plaza SW, Rm 4012; Washington, DC 20260-2200.