Call the shop and talk to them on the phone.
Does uprev have different maps that you can toggle through? Maybe youre on the e85 map or something like that.
Even if they can get it working right for you, id do a compression and leakdown test and post it for sale on here with those results (assuming they show a healthy engine). You should be able to get your money back.
The issue is everytime something goes wrong (just a matter of time with a hightly modified car) youll have to pay a shop to troubleshoot it, that's why its encouraged to build yourself and not buy, that way you know everything that goes on the car and what each part does and can troubleshoot it yourself.
Heres another link with your car also:
http://enkei.com/2010-nissan-370z-ni...car-show-area/