Kevin Mehrens was perturbed after dining at Grand Central Bowling’s bar last month, looking over his receipt and discovering that the business had tacked on an extra 2 percent to his bill.

Although the 2 percent amounted to only 40 cents on his $20 check, Mehrens didn’t think it was right. It wasn’t advertised anywhere in downstairs bar or on bar menus at the bowling alley, he says.

Mehrens filed a class-action lawsuit Wednesday in Multnomah County Circuit Court, claiming the Grand Central Restaurant & Bowling Lounge has “ripped off” thousands of customers in the past year with a deceptive charge.

With 20 cents charged here and 40 cents charged there, the suit estimates the “overcharges” amount to tens of thousands of dollars of extra profit this year. The suit says the money should either be returned to customers -- or if the customers can’t be found, donated to charity.

A representative for Concept Entertainment, the company that manages the 12-lane bowling alley, declined immediate comment.

The Portland-based company runs Grand Central Bowling, plus nine Thirsty Lion pubs in Oregon, Arizona and Colorado, according to its website. The bowling alley is at Southeast Eighth Avenue and Morrison Street.

Mehrens is a Portland civil attorney. He enlisted Portland consumer lawyer Michael Fuller to represent him and other yet-to-be-identified customers. Many customers may not have noticed the extra charge, the suit says.

Fuller told The Oregonian/OregonLive Thursday that little slips of paper placed on some of the tables in the bowling alley’s dining area announce the 2 percent charge and explain that the business is trying to “offset the rising minimum wage in Oregon.” Fuller said that’s adequate notice.

But customers who order from the upstairs or downstairs bar or bowling lanes have no warning they'll be charged an extra 2 percent because it's not announced anywhere on the menu or placards posted in those areas, according to Fuller and the lawsuit. The suit says that's a violation of Oregon consumer law.

Fuller said some businesses add service charges to customers’ bills, and there’s nothing unlawful about that unless they fail to inform customers beforehand.

The practice appears to have become more prominent since July, when Oregon increased the minimum wage, giving a raise to about 300,000 workers. In the Portland area, the wage jumped $1.50, from $9.75 an hour to $11.25 an hour.

Some businesses chose to raise prices. Others added service charges.

Mehrens' lawsuit claims that businesses that don’t advertise service charges hurt other businesses that follow the rules.

“By misleading its customers about the actual price of its menu items, (Grand Central Bowling) puts local businesses that do not misrepresent the price of their goods at a competitive disadvantage,” the suit states.

Fuller said Mehrens complained to staff and then Fuller sent Concept Entertainment a letter asking it to stop the unadvertised charges last week. But Fuller hasn’t heard back.

Fuller said the company has 30 days under Oregon law to agree to reimburse customers, and if it does, the lawsuit will go away.

“We would waive all fees and costs if they just promised to return all the money they’ve overcharged,” Fuller said.

Read the lawsuit here.

-- Aimee Green