Engine Knocking Noise problems of the 2008 Jeep Grand Cherokee

My vehicle kept stalling like it was running out of gas and I took it to the Jeep dealer. They kept my car for a week and couldn't figure out what was wrong with it. They told me it might be a fuel pump issue but they weren't positive so they asked me to pick up my car and keep a log. The second time it happened I took it back to the dealer and they kept my car for 5 weeks and couldn't replicate the issue. The customer service was awful. They basically told me they didn't know what was wrong and asked me to pick up my car. I picked my car up and the first day I drove it to work it left me stranded on the highway. The car started stalling out and I couldn't maintain my speed on the highway. I had the gas pushed all the way down and I was barely able to get up to 45 mph on a 65 mph highway. I had it towed to a different Jeep dealer which said it was the transmission which I had to pay to have fixed but I think it was related to the fuel pump issue and the transmission blowing up was a result of that not being fixed. The car is starting to have a knocking sound when I drive it again and I'm not convinced I won't be stranded on the side of the road again. It's completely unacceptable that when I had a problem with my Jeep I take it to the dealer and they don't know what's wrong and can't help me. If they don't know, who is supposed to know?? I feel that my children and I are unsafe in this car. It's unacceptable that a car just stalls out of nowhere on a highway and Jeep/Chrysler acted like they could care less. Like it was my problem and not theirs. They inconvenienced me for over 5 weeks and I still don't have a reliable car that I feel safe to drive. Completely unacceptable. Is it going to take someone being seriously injured or killed for Chrysler to do the right thing?.