According to court documents filed in London, the company set unlawfully high fees to stores when shoppers swipe their debit or credit cards, and it has been doing that for 16 years between 1992 and 2008.

The case was brought by UK’s former chief financial services ombudsman Walter Merricks who said "MasterCard charged billions of pounds of unlawfully high fees for its sole benefit and to the detriment of consumers." He is backed by law firm Quinn Emanuel, under the new Consumer Rights Act.

According to the law firm, the world’s second-largest credit and debit card provider MasterCard has spurned a chance to settle with the European Commission, choosing to fight its case through the courts.

After a 10-year legal battle between MasterCard and the commission, the European Court of Justice ruled in 2014 that the credit card firm’s fees for cross-border transactions were too high.

“MasterCard lost this battle at every level and showed complete disregard for its cardholders and consumers at large, focusing instead on generating unlawful profits,” Quinn Emanuel said in a statement.

MasterCard has denied any wrongdoing, saying it continues to firmly disagree with the basis of the claim and intends to oppose it vigorously.

"We deliver real value through the benefits of security, convenience and consumer protection, and we are committed to investing in our payment services in order to continue to meet the rapidly evolving needs of all our customers," said MasterCard.