Q: safari is locked, says to call an 800 number to resolve issue.

No, any such message will be a scam.

Do not interact with the message. Do not call any number presented.

Force quit Safari, then restart Safari while holding the Shift key.

Choose Force Quit from the Apple menu, close Safari, and then launch it with the Shift key held down. If the message reappears, disconnect the computer from the Internet and erase that site from the browser history.

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Click here and follow the instructions in the first paragraph of the last section.

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Navigate to Settings/ tap  Safari / select Clear History and website data

If it does not help your router may be hacked.  See Check the instructions on this page : http://www.thesafemac.com/how-to-manage-a-hacked-wireless-router/

- Reset the iPad. Nothing will be lost      

Reset iOS device: Hold down the On/Off button and the Home button at the same time for at

least ten seconds, until the Apple logo appears.

- Then as the link Neil provided, go to Settings>Safari and clear information