I completely feel your pain!!
My Liberty is a 2007 w/ 15K miles. Issues started within a month of ownership, at this time the vehicle had less than 2K miles.
Issues so far-
1) Excessive brake noise. Spent two days at the dealership before they determined "it's normal".....Issue still on-going.
2) Excessive dust entering into vehicle. Again spent two days at the dealership. They replaced the hatch seal. Issue resolved.
3) Transmisson leak. Spend one day in service, issue resolved.
4) The big pain in my stupid, on-going issue that started day 1. A waterleak that is saturating my passenger floor. The dealership has had the Jeep on 4 different occasions, totaling over 30 days, and still CAN NOT find the root cause. The issue started Memorial Day last year (literally two weeks after I purchased it) and still leaks today. As of now, the dealership claims they have a call in with Chrysler and they will be sending a service rep out asap (I say "claims" because they have been saying this since before Christmas).
Here's a thread I started.
http://www.lostjeeps.com/forum/phpBB3/vie ... sc&start=0
The dealership has the absolute worst customer service. It's mind-blowing- the crap they tried to pull. Here's one quick example- The service manager called last summer while they had my Jeep for the water leak. He asked I come and pick up my vehicle for a few days because they needed their loaner back. I agreed, but before I hung up, he said, "well your interior is completely stripped". I was like OK?? He said everything was removed, carpet, all seats (except drivers), center console, etc... I told him no way. What was I supposed to do strap my fiancee to the roof? I kept the loaner. 5 Star Customer Service

....Sure if that means F-ING over one customer to help another... That example isn't even the tip of the iceburg!
I have talked to the Owner more than once, the General Manager (Who is the owner's wife), and of course the Service Manager.....Deadend! I have called Chrysler direct, more than once and walked my way up the managment ladder.....Same responses as you, no luck, no help.
I received a call mid December, shortly after I brought the Jeep in for the fourth time. It was the Owner, he asked If I would consider "exchaging" the vehicle. I couldn't believe it, an end, so I thought. I drove down to the dealership, but they wanted me to do a trade-in, as if I were a regular customer.......Absolutely no way I was going to take a 7K+ loss on trading this thing in! As mentioned I bought the Jeep brand new in May 2007, they wanted me to trade it in 6 months later, that's a huge loss, they apparently thought I would take....Again, I was mis-lead by their 5 Star Customer Service.
As of now I'm overqualified for the Michigan Lemon Law, but have been reluctant until recently. I contacted the lawyer and he's confident we have a rock-solid case. Except for one catch. When I purchased the vehicle, I received an employee discount. I'm not an employee at all, it was out of the dealerships generosity. With this said, the lawyer said it's going to be very tough to win. According to him, employee discounts lock you into the vehicle and eliminate your Lemon Law rights. I of course, didn't belive it and got a second opinion. The second lawyer confirmed, he said there is a slight chance to win the case, but not too likely.
I could bitccch all day, but it's not going to get me anywhere. To the OP, good luck and I'd re-think purchasing from Chrysler again, I guarentee I done.