Haha.. cant it be solved by doing a factory reset?
Nope, factory resetting won't help. Once you're banned, that's it. I'll explain
very quickly and simply:
Your Switch has some keys that are unique to your console, like basically all modern consoles, that are generated once during manufacturing and are never going to be touched again. Some are used by Nintendo to identify your console. They're cryptographically secure, meaning that bruteforcing isn't an option, and changing some might make your console unbootable (
if they can even be changed, as some are written into hardware components like the CPU itself). So, in other terms, once your Switch is banned there's no way to manipulate or regenerate those keys and get new ones to unban yourself.
Now, you may ask: what about doing something like the 3DS, where you get keys from an unbanned console and inject/spoof them into your banned one? Simply put, it's technically possible but practically won't help. The main reason why it worked on the 3DS is that it sent very little information to Nintendo about the software running on it so we were able to do pretty much anything without worrying for a ban - sure, ninty tried to detect CFW and do ban waves but their method was shoddy as not all CFW users were banned, plus there were some unconfirmed non-CFW users who reportedly got banned too. On the Switch, however, Nintendo logs pretty much everything going on your console and you're going to need some kind of RCM payload to inject/spoof the keys, meaning that you might be initially unbanned but it's just going to be a temporary solution, then both Switches will be shortly banned.
TL;DR: There's nothing you, or anyone, can do. And it doesn't seem it'll change in a long while, if ever.