Forgiving the Unforgivable

So let's say you had a wonderful loved one that suddenly passed away. Okay, now lets say that you had him or her put down.... humanely and by professionals. The loved one is a dog. Then the same professionals lost your beloved dog's ashes. Actually, they lost the paperwork that was attached to the corpse of said doggie and therefore disposed of her remains e.g., threw her away. Now the paperwork to bill for the private cremation remained and was properly processed. Hence the title of this blog.... so how do I forgive the unforgivable?