When you say locked, on what device?
The TomTom or the router?
Are you able to connect other devices? If so then this is probably a TomTom issue.
If you think its a router issue you can try resetting it by using the pinhole which will reset it to factory settings. If you have changed you password or user name these will be reset to the original values and you will have to change them again.
If it's your TomTom you would be best to find a forum for this device.
From the 29th of March our TalkTalk Community will move to peer-to-peer support and the TalkTalk team will no longer be here to support with queries. Don’t worry we still have plenty of ways to reach out if you need to speak to TalkTalk directly. For more details check out the link here:
How to contact TalkTalk Broadband - Help & Support.
