It has been reported that someone has hacked into my device.

Apple doesn't send such emails or links. You've been visited by what is called a Phishing Scam. kb1951 is correct that if you have not jailbroken your phone, you can't be hacked.

See this link --> Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

A non-jailbroken phone cannot be hacked. Are you sure that Apple sent you a link? That would be very unusual. Hopefully you did not give any personal information away.