Problem with Moulinex MultiChop

I recently bought at Moulinex MultiChop, which was highly recommended. When I tried to use it for the first time, the large 'button' which triggers the machine refuses to move - it's completely stuck. The instructions contain NO troubleshooting references, and I find the website impossible to navigate to ask for help. This is not very impressive for a brand like Moulinex. Please can someone help/advise.