What would you do in this situation?
Do not panic
Ask for a field support engineer to be present on-site to start resolving all the issues ASAP.
Would you let HP repair a brand new printer?
Absolutely. There is no other way to make it work.
Demand to exchange it for a new one?
I'm afraid that is very unlikely that HP would agree to replace the printer. But it is HP's obligation to make your printer work ASAP.