I was thinking that the shielding on the antenna cable is weak and that the ferrites might be best on that.
If it comes to replacing the cable with something better shielded...one idea is to get a female joiner connection and pull the new cable through with the old...if it is not bundled and wire tied. I'd leave this one to the dealer though
Another alternative is to forget the existing mount and cable...maybe they could move the antenna to another location. You might have a "pre-wired" satellite location that is both better shielded and away from the inductive interference.
Hope the ferrite traps do the trick...try to get one in close the the microwave location and another near the other end of the cable. The more the merrier!