There is no singularity in the middle of a black hole.
At the Schwarzschild radius there is a firewall.
This firewall is a place where all things get very cold and very hot
(near 0° Kelvin and near at Planck temperature) at the same time.
Every elemental-particle is crambled in the firewall into pure energy.
Behind the firewall is no space and no time any more.
The black hole has no center point in the middle.
The firewall is not differentiable.
What is one Planck length before and after the firewall ?