I bought two identical items. One was fully functional from the outset, but the other came with an inoperative power cord (powered by a car lighter). I was pretty sure that everything else worked because the power cord from the first device was able to get the second device working.
Although I was initially disappointed that the product shipped with a malfunctioning power cord, I was delighted at the responsiveness of customer service. Because I did not need the entire unit replaced (only the power cord), I contacted customer service to ask if they could ship only the power cord. At every step of the way, customer service was responsive (less than a day to respond to all of my queries) and polite.
Suffice it to say that I will be doing business again with this company, should the need arise. In a world where many companies do not understand proper customer service, I am happy to say that this company stands above the crowd (and the product is great, also).