IIRC from previous discussions here, you can't call the fraud/audit department. Normally they contact you by email.

I'm confused by your "receiving end" comment. I had understood that someone was trying to use your account's status to get status with AA, UA, and AS. Do you mean that they were apparently requesting high status for your account? It could be a typo, but it could also be someone planning to sell an award ticket from your miles to someone who wants to fly with status.

When your DL account gets unlocked, you probably should change the password. You might want to consider changing other passwords too.