Question: Apple Authorized Service Centres
How may one reach Apple's central or top-level office for service centres? Any phone number, email-address, URL?
I have had an appalling experience with an authorized service centre's technician. He talked nonsense, lacked knowledge, and misled me, and I want to give the lowdown to the right people at Apple because they need to hire more knowledgeable persons and make sure they know what they're doing.
MacBook Air, macOS Sierra (10.12.3)