VPN providers can end accounts which violate their terms of use. If you look at https://nordvpn.com/terms-of-service/ for example, you see that they will terminate accounts violating their ToS. The same is for other providers.
How do they know you are violating their ToS when "nothing is logged"? That's contradicting as hell. According to a well known comparison chart, some providers which are serious about privacy are Nordvpn, IVPN and BlackVPN.
I am not planning to violate their ToS, but I am very sceptical about privacy in general.