[question] cloned/hack account?

Guys is it possible for someone on my network to use my account without my permission? I mean when the technicians installed my canopy, they knew the username and password. Assuming that I haven’t changed my password, is it possible that they can use those details and and connect thru another canopy (even if I’m currently connected to the network)?

If so, what should I do so that my ISP can verify that I’m the legit subscriber?

Thanks for any info.

Can you be a little more specific, are you concerned about the technicians knowing your password on a Wireless Router on your network?