good insulation - but weak cover or lever

I was very excited about the design, as the insulation performance. I bought the pot itself and did it well away again. The pitchers were both until recently in daily use. In both cases, the same error occurred:
- The pot was not drunk in the morning completely empty and was standing a couple of hours left (until they should be reinstated for coffee time, 16:00 clock,)
- The cooling inside a vacuum is gradually created with the lid closed
- In either case, the small lever not managed to open the lid, but broke directly on the axle, which leads the lever.

Conclusion: obviously the material is processed incorrectly or the lever for the sake of the design incorrectly dimensioned. The pitchers were both only 14 months in use!