Complaint Review: United Air Comfort

Rip-off
Installes AC unit, had problem from day one, they did fix some but the AC compressor is not working propperly and is to noise.

Been promissed that will be replaced about 21 day back.
I called 3 times, and every time I been told that we be there in 2-3 days. When I called back, they say that the compressor didn't arive yet. Now I can't get in touch with them, and need new compressor.
What can I do?

Thank you.

John
Northridge, California
U.S.A.