ur password was hacked, dat means u lost ur password
first,go to the mainpage of runescape,then you could a see a box called Account Recovery
choose Recover a lost password
type in your account name
then type in your email address
at last the Type of query:
choose i have forgottern my password
then there will be a next page
type in your recovry question(if you have)
then type in your previous password(the password that u login before)
at last type in the new password u want
wait 24hours
then jagex will send u a letter that u will get back the account
i have post the way to get back password in the following question and became the best answer:
http://hk.knowledge.yahoo.com/question/?qid=7006070300420
after u got ur password back
check ur bank,
if u didn't set a PIN, then ur items might be stolen
so set a PIN next time
and remembrer to change ur password frequently~