Where can i find a real support?

I brought my MacBook Pro to an authorized service provider, and it has now been in service for nearly four months. Whenever I inquire about the repair status, I'm told that they are still waiting for a some part to arrive.

I'm starting to feel concerned because, as far as I know, it typically takes about three weeks to repair a device.

On support page a can't find anything helpful. Neither in social DMs... Is there something like an old school email?