I have reinstalled the old bearings, they are in good conditions. All other Enduro bearings are already assembled into the wheels, they seem to be ok. I will return to the shop the bearings for the hub, one of them is unusable, I think it is defective.
Strangely, some of the bearings were packaged inside a sealed bag with Enduro logo, and some others inside a zipped bag with no logo, which makes me think...(bearing cost: approx. 4€ each). Probably bad luck, or most probably, newbie mechanic.
Anyway, for the next time buying cheap, use and throw, chinese bearings will be an option. But now i'll give Enduro bearings a chance.