gauss law in electrostatics is true for any closed surface ,no matter wat its shape or size is.justify this statement with an example

Gauss's Law :
The total electric  flux over a closed surface in vacuum is equal to 1/ε₀ the total charge enclosed by the surface.
if q is the charge enclosed by surface S, The total electric flux through the surface S is Φ=q/ε₀
while measuring the electric flux, surface area is more important than its volume or  its size.
Example: 
let us consider a closed surface S encloses a point charges +q1,-q2,+q3 and -q4, the total charge enclosed is q= q1-q2+q3-q4
∴electric flux across S will be Φ=q/ε₀=(q1-q2+q3-q4)/ε₀
The total electric flux is zero if no charge is enclosed by the surface.
conclusion:
The closed surface chosen for application of Gauss's law is called as Gaussian surface. It can be of any shape or size

According to Gauss's law, the electric flux through a closed surface depends on the net charge enclosed by the surface and not upon the size of the surface. For any closed surface of arbitrary shape enclosing a charge, the outward flux is same as that due to a spherical Gaussian surface enclosing the same charge. This is because of the fact that: (a) electric field is radial, and (b) the electric field, E directly proportional to 1/r²

Here, size or shape is not matter net charge is not what is inside the surface. this proves that gaussian surface is my depends on shape and size of the surface.