@ Heather2000
Please refer to the following solution post for information on how to go about the issue you experienced:
http://windowslivehelp.com/solutions/safety/archive/2009/04/29/recent-reports-of-account-hijacks.aspx
Regarding your sending limit, please reply to this popst so I can look into your issue.
You may also visit the following solution for information regarding the 24-hour limit notification that you received:
http://windowslivehelp.com/solutions/sendlimits/archive/2008/12/22/hotmail-sending-limits.aspx