1. New created particles - New pair of particles are created constantly around the SMBH (at the event of horizon or below).
If one particle carry a positive charge, the other one gets a negative charge.
For very small black holes, this would be true. This would not be true for super-massive black holes as they have insufficient tidal forces to produce anything other than photons, gravitons and maybe neutrinos. Charged particles like electrons, protons or muons have too much mass-energy to be generated by the (relatively) weak tidal forces present.
2. Magnetics field - Around the SMBH there is magnetic field. This magnetic field is quite strong at the event of horizon (or deeper?...)
Although true black holes cannot have such a magnetic field, I will submit to the possibility that something like MECOs (magnetospheric eternally collapsing objects) could, maybe, be what "black holes" actually are. So I will tentatively agree that "black holes" could be MECOs and as such could have magnetic fields. I'll consider this plausible for the sake of discussion: https://en.wikipedia.org/wiki/Magnetospheric_eternally_collapsing_object
3. Lorentz force - Based on Lorentz force, the magnetic fields deflects differently the path of the orbital new born particles pair:
Hence, if the positive charged particle will be deflected outwards, the negative charged particle will be deflected inwards.
Therefore, while the negative is pushed inwards into the center of the SMBH, the positive is pulled outwards and get's eventually into the accretion disc.
The Lorentz force would be there, but it wouldn't be "positive goes out and negative goes in". The Lorentz force would deflect the path of particles at a right angle to the field lines (assuming that they were already on a path perpendicular to the field lines. If they are parallel to the field lines, there is no force).
Would you kindly explain where is the contradiction?
The contradiction is your claim that this process causes the black hole to grow in mass. The mass of the black hole has to shrink, not grow, as the negative mass (not negative charge, an important difference) particle is invariably the one that passes into the hole (because the swapping of time and space coordinates inside of the event horizon is what makes that particular particle have a negative mass in the first place). That negative mass subtracts from the positive overall mass of the hole, causing it to become smaller. If you are willing to accept this point, then I will agree that your model no longer violates the first law of thermodynamics.