Advice on mail
I have experience
NEVER sign up for receipt and in principle do not sign anything without checking the package!
If you have signed up, something is wrong. You cannot make any claims.
You have already confirmed that you have no complaints.
Ask them what they have to tell you.
for example if you signed and opened the package found instead of the iPad - a brick. and all. your problems.
not signing and seeing in the package brick shell them, and demand your iPad or go to court. And they will reimburse both the cost of the iPad and the cost of all legal costs.
Experience is. And not once...