Hero Book random shutdown

Hello,
I received my HeroBook Plus in past December but it is not working.
Randomly, the computer is shutdown fully making a noise like spark. This happen in both, with an without charger.
Besides, after this it takes a lot of time to switch on, even hours.
I want to apply the warrantee and be refund but aftersales service is not answering properly.
Any recommendation?
Thanks
Jose