Wow so sorry to hear things didn't work out on your purchase with this particular CS generator. I can understand where you must be very frustrated at this stage. I've never purchased this type(or any) CS generator personally, though based on the the average costs, I'd say you should get far better treatment than you've received to date with this.
Having said that, based on what you've written and this is by no means empirical, it sounds as though your unit may be damaged. ie, I took the liberty of looking up a few video reviews and found that the stirring unit appears to move quite readily in contrast to your own observations: https://www.youtube.com/watch?v=sz042F6Ggl8
PS. thanks for posting your experiences, and I hope you can get your unit replaced quickly.