The next big punch has been thrown in the fight between retailers and card providers Visa and MasterCard over merchant interchange rates.

This particular battle stems from the antitrust lawsuit that has been bounced back and forth for years. The original grievance alleges a "conspiracy" with some of the largest banks to fix fees charged during credit card transactions. In 2012, a $7.25 billion settlement was reached for all merchants that sued. However, roughly 8,000 of them have opted out and appealed because they do not agree with some of the terms and the settlement total has dropped. This has led some companies to file their own lawsuits.

Today, Walmart joined the ranks, officially filing a $5 billion lawsuit with the U.S. District Court for the Western District of Arkansas. Like before, the suit alleges a conspiracy to illegally fix merchant interchange fees.

"If the settlement is approved, merchants would be broadly deprived of their rights to take action against the credit card networks for future damaging acts," a statement from the company said. "Innovation around new payment technologies stands to be stifled, and consumers would face continually increasing hidden swipe fees, which already cost them tens of billions of dollars each year."

David Evans, Chairman of the Global Economics Group, spoke about this with PYMNTS.com and said the original settlement came with a "hint from the Judge" that merchants should take the money and be happy. However, Walmart and other merchants that opted out to refile believe they will be able to put an end to interchange fees for good.