My phone logs show this : (most recent one first)
Name Number When Length
L7 SRVC CALL 720-685-6307 03-25-15, 11:04 AM 0:20
L7 SRVC CALL 720-685-6307 03-25-15, 11:04 AM 0:00
No message on voice mail. I have no idea who this is.
Used "L7 SRVC CALL" in search engine and these exact letters are associated with several phone numbers in different area codes and states across the US.