As a friendly hint, b*tching or threatening does not impress anyone here, we are all users just like you.
Why blame Apple immediately if something outside your Mac stops working? Of course, it can be hardware related: It can be the monitor itself, it can be the cable connection including adapter.
It can be as simple as the monitor being set to the wrong input and waiting e.g. for an HDMI or so signal... you wouldn't be the first and will certainly not be the last having overlooked that. Guess what, it could be that its mains power plug is out of the wall... 😉
If you have checked everything regarding monitor and wiring, including trying it with the same cables and adapters on a different computer (even PC is okay), then please let us know again here.
Thank you.