I don't answer because I can see who is calling on my display. They call at 1:03 in the morning, 6:00 am in the morning ....basically whenever they feel like it so I have gone in and blocked all numbers except for the 20 i input. It's a pain because I DON'T OWE THEM ANYTHING. I did a search about 6 months ago and they have a very bad reputation for their tactics/harrasement. Even an ex-employee quite because of how he was told to treat those he was calling. They change their name all the time and they have been and still are being investigated. There is going to be a summit on telemarketers in the near future because of all the complaints and how they can worm their way in and still call. People are mad I was furious and AT&T were not helpful AT ALL you would think since it's their system they could figure out a way so they could not get through without us having to block anyone but 20 people. But I had had it and this final call screening/blocking did the trick.
