Shahriyar Rezai-Hariri is suing the SoCal-based theme park in a class-action lawsuit claiming Six Flags “made the baffling decision to keep charging all of its customers monthly membership fees while prohibiting access to Six Flags Magic Mountain” as the coronavirus spread across the world.

In docs, obtained by TMZ, Rezai-Hariri says the park closed on March 13 but “unlike its competitors in the industry, [Six Flags] continued charging its thousands of customers monthly fees — at full price.” He also claims the company is able to keep charging customers "without their consent" because it has their credit and debit cards on file from when they initially bought the passes.

Rezai-Hariri is suing because he says it's unfair for Six Flags to deliberately bilk customers while its parks are closed. He's suing on behalf of all customers dealing with the continued monthly charges ... and claims damages will exceed $5 million.

It should be noted ... a rep for Six Flags told us last week it's only charging pass holders who elect to continue to pay. And, those that do will get rewarded with a free pass upgrade. Those who do not want to keep paying are instructed to reach out to the company.