After four attempts, the MacBook I'm using for production was finally serviced and repaired on an Apple Authorised Service Provider.
Actually, the keyboard, the battery and the top cover were changed. When I asked how to prevent those issues from appearing again, I was answered "Nothing!", as the culprit is the very design of the laptop.
I don't know how much money this repair has cost to Apple, but my guess is Apple managed to pass everything on to subcontractors and suppliers.
But I do know how much it has cost to me. Calling the support and opening a ticket (4 times), making an appointment (3 times), backing-up and restoring the computer (3 times), going to the repair shop (2 times): the time I've spent to get my laptop repaired actually exceeds the price of the MacBook. And I am not including the lost revenue as I'm using that laptop for production.
This is just unacceptable. I have a strong feeling that Apple no longer focuses on quality and ignores its customers.
So Apple, you're loosing a customer, but you don't really care, do you?