This thread seems to be old, but this number is still around - they called my cell phone today. I never answer when I do not recognize the number/if it's someone I do not know. They left a recording on my voice mail with a "case number" and the usual "call us back or litigation will be started against you", etc. The call back number they left is 888-512-5897 which when I googled it, didn't have much information. I'm not calling them, just blocking them and making sure I'm on the DNS list. Scammers!!!!!
If you have an android phone just download some app from the Play Store and block the number. They will call and your phone will pick up and hang up on them. I did that and now I dont have to worry about it. The calls have stopped.
You can get on the DNC list all you want, but if you give your info to someone - ANYONE - they are exempt from the DNC list. You can then tell them to DNC your number in their in-house DNC and they have to, but there's no way to confirm if they do. Those are the magical words: DO NOT CALL me again.