Locator Number?

I called citibank today to talk to them about payment options. I have two accts with them. One was previously on a payment plan and we stopped making payments. When I called them, they said this one account has already been sent out. I asked to where and she couldn't/wouldn't give me an answer and said she could give me a locator number and to call them. She gave me the number and it is a phone number 1-800-248-4284. I called it and it said I reached the central locator or something like that. I didn't wait to talk to anyone. I am going to call back but does anyone know what this means? The account was less than 120 days late I believe (from when I stopped making payments on the payment plan).

Thanks!