...Got a C320 that won't turn over. Battery has a voltage of 12 when standing. Replaced with a new Battery and still have the same issues. Any suggestion why it's not turning on(turningOVER).

Does the key turn? if not possible key or electronic ignition switch (eis) is dealer repair only.
Key turns- check fuse #52 under hood, see if starter relay is ok. Jump relay starter should turn engine over.
If starter works with relay jumped and relay along with fuse is ok. you are done, you will need a scan tool from there.