Gorilla headlamps faulty

Bought and returned 2 Gorilla Headlamps at Builders Strubensvalley. When you switch the headlamp to “swipe” mode, it comes on and then with head movement, it switches on off periodically (almost like a short)? The sales person opened 2 more and tested with me - they all seemed faulty. I’m extremely disappointed as the Gorilla price point vs the original expensive Lumeo’s brand is excellent, but only to be let down by quality