general problems of the 2016 Chevrolet Silverado 3500

Hello I purchased a brand new 2016 Chevrolet silverado k3500 ltz dually from (xxxx) in lakeville, mn Feb 2017 I had approximately 25k miles on it and I had noticed the front tires were starting to feather and making a strange noise and the tread stared to chunk off. So I brought it in to the above dealer and they get michelin to cover 30% for a new set of front tires which still cost me approx. $700. 00. Well 6 months later I have 21k miles on the new tires and they are starting to do the same thing I brought the truck in to the dealer two weeks ago to have them assess the situation and have yet to hear back from them. So one week ago today I called gm directly and they told me they would call back with in two business days and or no later than Friday. Well Friday has passed I do not know what to do I use this truck to make my living and I am very concerned about safety and the pre mature wear on the trucks front end components. There is a strange vibration in the front end and it pulls to one side or the other on the freeway the dealer has aligned the front end with no results.