SOUTH CHARLESTON, W.Va. -- South Charleston Mayor Frank Mullens told the City Council Thursday that the more the city investigates the tax implications of the U.S. Postal Service incorrectly listing some city addresses as Charleston, the more problems they uncover."It's gotten worse," Mullens said.Charleston's $2 user fee assessed from everyone who works within the city limits is being mistakenly charged to employees of the five 7-Eleven convenience stores located in the city and Sherwin Williams, according to city documents.Mullens urges everyone who works in the city to check their pay stubs to be certain they are not paying the Charleston user fee."If you are paying taxes and fees in error, you deserve a refund," Mullens said.Consumers and employees are urged to contact city hall to report problems, he said."Call the mayor's office," Mullens said. "We will try to help you get your money back."Most businesses that incorrectly charged the 0.5 percent Charleston sales tax to consumers have corrected the problem, Mullens said, but the confusion has made it a difficult fix."Sherwin Williams has been particularly difficult to deal with," he said. "They won't take our word for it that we are not Charleston. To be fair, to the businesses are victims of this address system, too. They don't know any different. It's not their fault. This is a problem at the post office and they need to get it corrected."The city has "brought some heavy-hitters to the table" in efforts to correct the financial challenges residents and the business community are facing because of the mix up.Sens. John D. Rockefeller IV, D-W.Va., and Joe Manchin, D-W.Va., and Rep. Shelley Moore Capito, R-W.Va., addressed a letter to U.S. Postmaster General Patrick Donahoe this week urging his immediate action to correct what they believe is a result of zip codes 25303 and 25309 being "improperly coded by the United State Postal Service or its software contractor.""They understand the problem and are doing what they can to help," Mullens said.Officials are looking at several options, including the possibility of designating a new zip code especially for the city, he said.Mullens said he believes this problem will be solved, but has not ruled out legal action."If we have to go that far, we will," he said. "But once it gets to the point of legal action, it starts costing everyone."In a related issue, West Virginia American Water Company routinely charges a municipal tax. The investigation into whether those funds are being applied correctly is still underway. City Treasurer Hannah Pettit has a meeting with water company representatives scheduled for Friday.