It's admin's rule that in game actions are not able to be appealed. Fact is, it used to be one nation per person, but that rule got abused by people pretending to have a million brothers and sisters and what not. So the rule got changed, its now 1 nation per IP. Which means very separate people living under the same roof can no longer have their own nations. If your nation was deleted for that reason, then you were sharing an IP and there was clear evidence to support the action. I understand your argument, but there is nothing i can say.
My only suggestion would be to pm a senior game mod and perhaps ask them (nicely) to double check the deletion to satisfy yourself its not just a clerical error.