2005 Dodge Neon Rough Idle on Dodge Neon

I have a 2005 dodge neon that I purchased new from the dealer and since it was about 6 months old it has idled rough and shakes/jolts. It has become increasingly worse over the past few months. I have taken it to dodge at least 15 times and they always tell me it's the spark plugs, which have been replace over 5 times. 2 days ago I replaced them and the wires again just to find that it didn't help. I have ran fuel injector cleaner through, used only premium gas, etc. And no improvement. It seems to happen in drive, neutral, reverse, park, etc. Whenever I am idle and is slightly worse with the a/c on. When it happens it feels like a sharp jolt and the lights slightly dim and the rpm drops briefly, this continues over and over (like little seizures) until I begin moving again. Every time I take it to dodge I am charged $150 to tell me to change the spark plugs. I am sooo frusterated and I don't know what to do. What could be causing this issue?