It's probably because they were reselling single accounts as one and making huge profits. I think Ahrefs have changed their login system because when I login on one computer, it logs me out of another. So multiple people can't use the same account at the same time. Don't quote me on this but that's what it looks like.
wtf man. like 5 days ago they said theyd be back up in 48 hours. 5x24 = not 48
getting pretty annoyed with this terrible service
You're idiot.. I don't know why you're annoying if you know what are you doing is illegal. (Ahrefs Terms and Conditions)
Stop complaining and buy your own ahrefs subscription (I'm sure you can afford it.)