O my goodness I would be spitting feathers if it was me. The account was hacked regardless if it was because you used your email and game passwords the same.
Plus the fact you have the log in email showing it was from China.
It is a very bad representation of Arena Net not even giving you a personal answer but almost a copy/paste. If it was me I would be appealing them again or trying to contact them by phone somehow but then I am pretty stubborn with things like that. I have luckily never been hacked though I had friends have it happen to.
So sorry to hear this hon