Chevsince20

I purchased my 2012 Captiva LTZ used in 2013. I started experiencing acceleration issues within first year, thought I purchased bad gas. Blamed it on myself. Then I was starting to lose power while driving, the head lights would dim, cabin lights would go dim and the vehicle would start chugging. This happened at night, in October of 2015. I managed to drive it to an Auto Zone and had them change the battery, the voltage reading was extremely low when I checked. The new battery seemed to solve the issues, for a short time. Sometimes when accelerating there is no response from gas peddle being pressed, all other functions seem to be fine but no acceleration. I would let off gas and try again, then chugging and finally it would go. Since November of 2015 I am now experiencing the slow acceleration along with a key that cannot be released from the ignition. This does not happen all the time but has become more frequent. I managed to get the key out most times, within the last two weeks it has been stuck for 2 days sometimes 3. I've had to resort driving around with a booster pack just to use MY vehicle. This is not safe! Vehicle has been taken to dealer multiple times since November, they have it now and are trying to recreate what has been happening, till they experience the issue, they see no problem...