Rear Suspension Springs problems of the 2014 GMC Sierra 1500

I have a 2014 GMC sierra, I took my truck in to get it serviced, 2 weeks ago. At the time, when I was reversing you could hear a clicking noise, when I would back up, or brake, also going over any bump in the road, at very low speeds, ( exm. 5 mph to 15 mph), well, the dealer came back and told me, my break booster had to be replaced, and they lubed and cleaned my u-joints and lead springs on the rear end. Well here it is 2 weeks later and the problem came back, and I called the dealer, and the response I got, " just bring it back in, and the only thing we can do it re-lube and re-clean it, but that's all we can do for you". My husband owns a 2013 sierra, and he has had no, issues with his truck what so ever. This is my 3rd vehicle from GMC, I have been satisfied up until now, there is a serious issue you need to look into. The truck drives fine, but, with this being a new truck, this noise should not be there, I am considering trading it in and going elsewhere for the money I am paying on it.