Poor customer service

That depends on where you are not receiving the service that you think you should get. If it’s in this forum there is no point, because it’s just users here like you. If it is online click on Get Support and ask to speak to a manager. If it’s in an Apple store go to the store and ask to speak to the manager. You can also write to Tim Cook (snail mail). While he won’t see it, someone from his staff will get back to you.

Depends on what your issue is. Perhaps post information so that someone can help you.