I am so sorry for you and the loss of Bella. I agree with what all of the others have so far said. Get a lawyer asap. And also that the employees of each store are probably told by corporate not to admit any sort of guilt on their part as well as to stonewall you to the point where you will give up calling, going to the store, etc.
To accomplish anything at this point, you need a lawyer.
God bless you and wish the best of luck to you and suing the asses off of PetSmart.
Just because they are such a large chain does not mean that they are infallible and guiltless.
I wish you the best.
