My experience is the same as Jennifer's: When I answered, after one ring, there was on one on the other end of the line and when I tried calling back, the call disconnected immediately with no answer.
Well, I didn't TRY to call back. But I received 2 calls within an hour of each other. Only rings 3 times the second time so you can't get to it anyway.
Elsewhere on this site folks complain about multiple incoming calls from the same or similar numbers. All have the double 55 following the three-digit local exchange.
I'm just going to report the number to the FTC. This is usually very effective and you can do it online. (Just google FTC online complaint form.)