Engine Noise problems of the 2014 Chrysler Town & Country

I bought a 2014 Chrysler town and country in August 2014. I took the van in for a squealing noise 20 days after I bought the vehicle sat there for an hour at the dealership and then they come to tell me they could not hear the noise. The van stop making the noise in October 2014 however it almost cost me and children our lives. We were driving down a very busy highway where we live and the engine stalled and just quit lost all power I was able to get out of the road thank goodness or we would have been smashed because it was 8:00 a. M. Work traffic. I then called the dealership right away and made an appointment to bring the van in to have it seen about. I took the van in and was called a few days later and they told me they could not duplicate the issue very frustrating. My van has stalled several more times after that and has been at the dealership for 3 weeks now and they still say they cannot find the issue. Also, I was in the parking lot of a store and turned into a parking place and the engine just shut off it took several minutes for it to start back up. I have contacted Chrysler on this matter and they go with what the service department says and if they cannot duplicate the issue they tell me to come get it. I am now going to turn this over to the lemon law department because I do not feel safe in this vehicle that was purchased new and only has 7,000 miles on it. Not to mention this is the second brand new vehicle I have purchased from this place and the first one the transmission went out at 6,000 miles. I need some help someone please advise me on what I need to do. Also, I have wrote a letter to Chrysler stating the problems I am having and certified mailed it and the only response I got was I will send to someone else.