Casual Shoes soles are falling apart

I have purchase Thom McAn shoes in past from Kmart with very good results.  I purchase this pair on June 26th and soles of this pair are having very poor wear. I noticed first that the heel area of the right foot had a hole.  These shoes have a work boot sole.  I was surprised that wasn't a solid piece of material, but voids inside the heel.  Obviously the material used for the soles are not hard and solid enough to handle normal wear.  Same problem now on the left foot too and now the sole is splitting apart in several places on these shoes.  The interior of shoes also are also showing excessive wear.  Just two months of wearing them and they need to be replaced.  I've had Thom McAn Shoes lasting several years for a cheaper price do much better wear performance, but this experience really turns me off ever purchasing another pair.  Some one at Thom McAn or Kmart needs to investigate such a poor quality is now being produced for them.