2015 Jeep Cherokee cruise control problems

2015 jeep cherokee sport was purchased in october of 2014. Around end may 2015 experienced problems with braking. While coming to a stop sign brake would be pressed down but vehicles rpm's would rev up and vehicle would start accelerating forward. Vehicle was brought to shop after finally being able to make an appointment on 06/16/15. Mechanic was able to experience the problem and reset module on vehicle. But check engine light came on.

Going down hill, the car accelerated 8 to 12 miles an hour faster than the cruise was set for. Car keeps accelerating until you hit the brake. Does not hold the set cruise speed limit. I brought it to the dealer and after 1 1/2 hours they told me my cherokee limited was not equipped with an adaptive cruise control with stop and go. I was told by the service writer I just have to hit the brake until the decline is over and then hit resume on the panel. I know this is incorrect so is there a fix for this?