Stanley Thermos Leaks Heat

Stanley does not stand behind the thermos it sells. They sent the thermos back from technical service, claiming there was no problem, even though it could not keep heat for the promised time. The product, which is advertised as keeping liquids hot for 12 hours, becomes too cold to drink in just 3 hours. Do they think we are lying, or that we will be too lazy to follow up and simply accept a defective product? They are wrong. If my product is not replaced, I demand a refund. They also claim the thermos has a lifetime guarantee, but this brand has been a disappointment. Two out of the three thermoses we purchased had the same issue.