Registration code for Dell Digital Locker

Help me! I want to flash my Wyse C10LE, but I bought it through an online auction. To download the firmware I need a registration code, and I was not given, what should I do? I have already applied for re-registration of the product to me, but I did not answer, because I do not know the name of the previous owner and he does not get in touch, what to do in this case? I can even throw off a photo of the thinnest client that you were convinced that I have it. Sorry for my English. I simply don't know him