Guys guys this thing happened with me too. And I am writing this comment right after fixing the issue and let me put it out for you guys really simply.
First of all you wanna leave it charging it for half an hour so that it could have some juice to jumpstart. Then you need to take a knife, scissors anything you want and gently scratch with it on the golden charging pad the surface of the band and charger for a while and immediately plug it to a USB source and thank me later on