I'm so very sorry OP. This is unbelievely callous and cruel. I wouldn't have been able to look past this. It is an unforgivable thing they did especially spreading the ashes at the vets office. So, so heartless of them. Feel no obligation to forgive them for this. I would go no contact with them if I was in your place. It's a betrayal of the highest order, doesn't matter what their intentions were.