Don't know that car but my daughter had a fault on her cable operated gears on her car that was an easy fix,look down on the gearbox and you may see a twin cable setup going to the selector (get someone to move the gears while you locate the working end) my bet is that he replaced the cable but crossed the ends,if you push the lever it will pull the selector,if you pull the lever it will pull the selector the opposite way,as he has replaced the cable the fitting is more than likely wrong.Good luck.
Rich t
October 2014