OAKLAND (KTVU) -- 2 Investigates has discovered that at least a dozen customers of a local window company who purchased high-efficiency windows "didn’t get what they paid for," according to a former employee.

KTVU obtained contracts from at least a dozen customers all across the Bay Area who purchased Low E3 glass from Anamar Window and contractor Clear Vision Windows, based in Hayward. But former employee Mark Torres claims that many customers didn’t actually get Low E3 glass for their homes, but instead were given a lower, cheaper grade of glass -- without their knowledge.