准备打电话。 沟通问题。 决定是否要更改无线网络密码。 要求客服为你推荐正确的安全设置。

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
Gather information that the support agent will need to verify your identity, such as your account number or billing address. Tell the support agent that someone is using your wireless connection. If your wireless modem/router came from your ISP, they can log into it and remove unauthorized users. If you think someone is using your password, ask your support agent to configure a new one at this time. Remember, passwords are case-sensitive. If it’s been a long time since your router has been updat