I think in both cases of which I am familiar, the orders were placed directly with Prusa. Joe Prusa is well known for a very high level of quality customer support. The second maker managed to connect a wire incorrectly, damaging a small component. He had a replacement, no cost, a week later, even though he recognized it was his error. Also, Prusa's email support is equally high, as well as the support information on the web page.