I don't know whether it was a problem on my side on on theirs, but when I contacted the company I experienced that the customer service was very kind and helpful. Seeing reviews here of people who had problems with J! NX made me worry, but everything was fine for me. Response was within 24 hours (which was fortunate because I intended to preorder a limited item :) ). Thanks again to "Crash" Landon from support team:)
Can't tell you about the speed of delivery, but I don't expect any problems there, either.