Battery problems of the 1998 Chrysler Concorde

Purchased car in March of 2001 and had car maintained according to suggested repair schedule. In July 2001 engine began making a knocking sound. Returned the car to the dealer later that month describing the problem. I was told by the dealer repair person that I needed to have the engine replaced. I asked the dealer what had caused the problem because I was maintaining the car. I was told that the car could have came out of 'time' and the engine may have slipped. Repairman could not give me a suggestion on how this could have happened. It cost me over $3,000 to have the engine replaced with a used engine. The repairman at the time allowed me to keep my vehicle in 'storage' until I was able to pay the repair bill. A year later I finally was able to get my car back. I had the battery replaced when the vehicle was picked up (in Dec 2003). I noticed that the engine light was still on. I asked the dealer repairman (new person, other repairman left company) why that was. Repairman claimed that it was caused because the car sat for so long. I contacted Chrysler corp. About the issue and was told that I would have to work it out with the dealer. I am still experiencing problems with this car I. E. Acceleration problems (slow/ or sometimes rapid), leaking from what appears to be the engine (I am taking the car to a authorized repair shop (not the dealer - michael Chrysler, I do not want to deal with them), the engine light is still on. I don't not drive my car at excessive speeds nor do I do extensive driving, just local driving. I think this car is poorly put together. I know other people who own Chrysler and are experiencing similar engine problems. Chrysler should investigate these problems. I do not have money to keep paying for repairs on this vehicle and also the financing. I have spoken with the financing company (americredit) about the situation. I don't know what else to do get this car in at least drivable condition.