IMy cell phone number is on the national Do Not Call list and I keep getting sales calls on my cell phone. The most recent came in on 02/11/2014. I would like to know if it is a scam.

I got yet another call from 313-160-9948. The person claimed that I was eligible to win an iPad and when I asked them if they scrub their call list with the national do not call list. the answer was they didn't know about a do not call list, I didn't enter my cell phone number into a contest or anything so how did they get my number

I believe this is a scam I've not entered a contest to win a ipad