Why my two coils don't repel each other?
There will be some interaction but very small compared to using a permanent magnet and a coil. The magnetic field produced by the coils will be individually weak hence no apparent interaction but the magnetic field strength from a permanent magnet will be massive in comparison and this is enough to produce a noticeable effect.

Have you tried winding the coils around an iron core to increase the flux density? Here's a formula that should give you some general idea about the force from an electromagnet acting on a piece of magnetizable metal: -

Force = \$(N\cdot I)^2\cdot 4\pi 10^{-7}\cdot \dfrac{A}{2g^2}\$


F = Force
I = Current
N = Number of turns
g = Length of the gap between the solenoid and the magnetizable metal
A = Area


Detail above taken from here