How to file a complaint about apple support not performing?

Apple support is ridiculous. It is third time that I wait for the 2nd line support engineer to contact me at agreed time. No contact, then proposal of new time and again - no contact. This is closer to some small business than to biggest company in the world...

How to file a complaint? And I mean complaint, not feedback to apple. I want to get answer why this is happening. I spent $10000 with this company products and I deserve at least short information "sorry, the call will not take place at planned time" or anything like this, but instead I get ignoring from the company employees.