That suggests to me that the source of the problem is your laptop (and not the ISP).
He could be using the same isp or wap that he was using
at the hotel. One way to tell would be to close port 113
at his software firewall and if it stops then it's on the
laptop. If not then close 113 on the network if it exists.
If neithor of those stop it there's only one more point
that would respond and also have his real name info, isp.
