MasterCard operates one of the largest credit and debit card payment systems in the United States. As of the date of publication, more than 22,000 banks, credit unions and other financial institutions issue cards with the MasterCard logo, according to Yahoo! Finance. However, as a company, MasterCard International does not issue credit or collect payments from card holders. Disputing or canceling MasterCard transactions is possible, but card holders usually must follow guidelines established by merchants or financial institutions. You can dispute a MasterCard transaction by telephone or in writing, but phone inquiries are often fastest.
Step 1
Contact the merchant directly about the transaction. Merchants can cancel transactions and issue refunds to your MasterCard debit or credit card. Get the telephone number for the merchant from the receipt for the transaction, or check your MasterCard statement. Review your bank statement for contact information on debit card transactions. Explain your situation when contacting the merchant. Ask the merchant to cancel the transaction, if applicable. Or tell the merchant that you are disputing a charge appearing on your credit card statement. Reasons for canceling a transaction could include removing a charge for a deposit on a service or product, such as a down payment on a vacation package.
Step 2
Call the financial institution issuing the MasterCard if you cannot resolve the issue with the merchant. Check the back of the card for a customer service number for the financial institution. Explain your reason for canceling or disputing the transaction. For example, explain that you officially canceled your gym club membership but the gym continues charging your card. Or tell the bank that an unauthorized charge appears on your MasterCard statement and the merchant refuses to issue a refund.
Step 3
Contact MasterCard directly if the merchant or financial institution both deny your cancellation request or dispute. Call the MasterCard Assistance Center at 1-800-307-7309, as of the date of publication. The assistance center cannot make decisions for merchants or banks but can contact them on your behalf to encourage a resolution.