2013 malibu eco 2.4l no compression or power...

I purchased a malibu and it has no compression when u crank it.. wuts is krazy is the key gets stuck everytime u put it in there.. can't shift out of park unless u push button under the shifter cover... took to shop they Said they couldn't even get power to it for it to do anything.... they told me it is a problem with the hybrid system itself... I dont know wuts going on but I was told the car was left in the ACC position for 3-4 weeks then when figured out car was left on and key was stuck waited another 3-4 months to put new battery in it and nothing since then.. he said car ran perfectly fine and got 32mpg b4 it stopped working..tried changing battery in front, but don't know it the bigg battery in the back is affected @ all... plz can anyone help me figure this out