car won't start on 2005 Chevrolet Malibu

i bought a brand new battery a week ago it wont turn over alt. fine had it checked when i got battery. what could it be?

Asked by for the 2005 Chevrolet Malibu
Double check that the battery cables are tight, the shop may have left them loose. If that is ok, then you could have a starter problem, or the circuit that controls the starter (ignition key and switch, wiring, transmission gear selector etc., starter relay) Is this the same problem you had that made you replace the battery?
I recommend to check the cables, if they are OK, take it back to the shop that replaced the battery and checked the charging system.
Ask if they checked for something draining the battery. Something could be staying on intermittently, like a trunk light or radiator fan, and draining the battery.
No it was making a sound when the battery needed to be replaced