HOUSTON, TX --Whenever you fill up your tank, you trust the numbers on the pump to tell you exactly how much gas you're getting, and how much you're paying. But what happens when the pumps are wrong, and you don't know it? A local chain now must pay millions for lying to its customers. SunMart has dozens of locations throughout the Houston area, but after an investigation found they were in fact shorting Houstonians on gas, they've now been ordered to pay millions of dollars. SunMart customer Salvador Arguello just put his hard-earned money down for $5 worth of gas. He also just found that a Harris County jury handed out a $30 million verdict against SunMart gas stations for cheating customers out of every gallon of gas they pumped. "Cheating you out of your money, that's messed up," Arguello said. "You work hard for it, too." In July 2008, the Texas Department of Agriculture launched an investigation after SunMart gas stations routinely failed inspections. Thirty-five SunMart locations in the Houston area were cited for shorting customers on gas. "If I'm paying you for a gallon of gas, I should expect a gallon of gas," customer Mia Robinson said. "The economy's bad, and you're trying to rip people off." SunMart, which has operated in the Houston area for the last 30 years, released a statement on Tuesday's verdict saying, "We are very disappointed with the jury's verdict and believe there is insufficient evidence to support it." Manjit Singh said he purchased one of the SunMart convenience stores just five months ago and added that owners do not receive pump calibrations. "We don't have nothing to do with the gas," Singh said. "They (SunMart) are the ones who control it with computers and stuff like that." Those state inspectors ordered the pumps be recalibrated, but Arguello is now questioning his regular stop. "I'm gonna go look for another spot," he said. While the state is now seeking a permanent injunction to stop SunMart from calibrating its pumps, SunMart told ABC13 it is planning to appeal that Harris County jury's decision.