Who called from 3015409777

Answered...heard a foreign voice mumble something,
silence,then they hung up on me.
This is stupid.

301-540-9777
caller Id verizon

called at 10:00 am this morning.When I answered I heard a
foreign voice mumble something I could not understand.
I think they said "hold on" but not sure. So I waited
just listening to a silent line, then they hung up.
Who is this? This is stupid. When I Do answer,its still Nothing.
What do these people want?

The next day 877-642-1263 called.
I think its connected.
This is stupid.