I'm sorry, but I am not sure if I understand your question? You have his name and phone number and address? Or do you need to find out that information?

If he changed his ISP that fast, then he was most likely hacking you by using someone else's bandwidth such as wardriving. If you have all that information and just report it to the right authorities, but unless there was substantial damage done to you...nobody is going to do anything about it.