Can someone help me because someone hacked my runescape account?

Yes. You need memorable recovery questions and they should be unguessable. Also, make your passWord unguessable and never tell anyone. If someone says they're a Jagex Moderator and they ask for your bank PIN and for you to say the first letter of your pass, then the rest, they're not a mod. They're trying to steal your account. Report the account who was a "moderator". TIP: Jagex Moderators will never ask for your PIN or passWord. Also you can use recovery codes this is a different person