I hope you really mean they charged $130 for the install. If it truly was $1300...
RUN AS FAST AND AS FAR AWAY AS YOU CAN FROM THAT MECHANIC!!!!! A non-handy DIYer can should be able to do it in 3hours or less FWIW.
Anyhow, sound like it could be a couple of things - mis-aligned shifter cables, loose cross bolt, ill-adjusted end stops on the shifter etc. First thing I would do is pull up the shifter boot and have a look. Take a picture of it from as many angles as you can and post them here for us to diagnose further.
If you don't know how to pop the shifter boot, do a search on short shift or shift knob replacement in the archives for details.
Good luck!