my contacts are all missing and at&t support won't help recover them.

Emails are being sent from my contact list. I have contacted Yahoo. AT&T support. left several messages regarding my account being hacked and that all my contacts are missing. The only response from them was. 

Hi Anita,

Thank you for contacting Yahoo Customer Care.

I understand that your contacts are receiving email appearing to be sent from your Yahoo account, but they are not. I would be glad to help you today.

Scammers are always looking for ways to get personal info with malicious intent. While no one else can sign up for the same email address that you use, there are ways people can gain access to your account or send emails that look like they're coming from you. Be aware of how this happens and the steps you can take to stop it.  

Blah blah.,  nothing about where my contacts went to or how to get them back. any suggestions besides change to gmail