Battery problems of the 2000 Jeep Grand Cherokee

I have been experiencing a problem with my battery not staying charged. The first occurred when I had let the car set for about 2 days, it would not start. The battery would not jump. I had to buy a new battery. The battery post always get corrosion on it. I have had it cleaned and changed a couple of times, and it still gets corrosion on it in 2 days. I was told about two years ago that it could be the wires that run from one of the post to the engine. This time, my new battery only lasted about 3 months. Same problem. The dealer told me that I would have to buy a new battery. It appears that something is draining my battery, but no one can find out what. I had to get a new battery, but I am afraid that it will get drained also.

I have a 2000 Jeep Grand Cherokee laredo. In early December I was driving the vehicle when my engine light illuminated. I immediately called my mechanic, who happens to work for midas. He told me to bring it in right away. Because I live closer to midas than any Jeep dealer, and because of the service I have received in the past from Jeep/Chrysler, I took it to my mechanic. He advised me I had a blown head gasket. I received an estimate from him and he also advised me that the dealership would be considerably more expensive, I allowed him to repair the vehicle. After the repairs were complete, I talked to my mechanic and he advised me to contact Chrysler/Jeep and ask for reimbursement. Here in lies the complaint. When I contacted the dealership, bob dance Jeep in oralndo, I was told there was nothing they could do to help because it was my fault I drove the vehicle "hot". I explained the reasons I took it to my mechanic as opposed to the dealer and I was told so sorry. I then try to contact the warranty people for the vehicle. I was told I only had a 3year 36,000 mile warranty and that I wasn't able to do anything about it. The vehicle had 49,000 miles at the time of repair. I asked if I would be allowed to purchase an extended warranty and was rudely told no. This is only one example of the customer service I have received since purchasing this vehicle in July 2000. I have also replaced the transmission, two bateries, repaired the window which did not work and had the rotors cut three time. When I spoke to Chrysler headquarters, I was not surprised to receive the same response. I was told because the work was done by an independent garage,midas, I was not entitled to any type of reimbursement, period. I don"t trust Jeep/Chrysler. I don't want them working on my vehicle. Someone please help me!!.