First of all don't get an animal if you are expecting them to be perfect and never have any problems! Just like your own children, they can get upset or just have some problems that you have trouble correcting. You are an IRRESPONSIBLE PET OWNER if you get an animal and return it, and you should never get one again. DON'T GET ONE IN THE FIRST PLACE if you are not ready for the responsibility!
Back to the question at hand:
My little dog was having separation problems and would pee and poop in his crate while I was at work. I came home to find him a mess! It was disgusting, always having to clean him and clean the crate. I tried the safe room, everything! What I finally ended up doing was adopting another dog. A friend for him. Now my little dog has a little sister and doesn't feel the separation anxiety so much. As a result, the crate is now clean and I no longer hear the crying and whining in the crates. My 2 dogs absolutely love each other!