I had the same thing happen to me. It's a scam artist and now I have just reported them to the Atlanta GA police. They have nothing better to do than to harass people. They are trying to get your information and sell it to everyone else. Please do me a favor and contact the local police. Thanks.
NOTE: They say they are ATT, but they are NOT. Caller ID states "AT & T Service Ctr".
Allegedly per my callback to this phone number, this is E-tech/Epix, offering a free 30 day trial of their channel. But when they ask for the last 4 digits of your credit card number, your hackles should go up. Way too much fraud/identity theft in our world. The rep told me they have access to our ATT account info, but what company hasn't been hacked? I never give any info out until I am sure who I am dealing with.