I receive calls constantly from this number...they leave a voicemail but its all garbled...like possibly an automated dialed call....no message... I have no idea who they are.

Same here - several calls a day - no caller id - voicemail is totally garbled.  I'm sure its an automated call waiting for someone to answer..I have no idea who they are

Called every 15 minutes for about 2 hrs in the morning, comes up on ID as Chase City, VA. Not positive but I think Pentagroup is a collection agency for Dell and possbly other companies.

called regarding a supposed debt for someone else who lives at this address.  requested something in writing..was told that could not be done.

YUP.. dell collection agency, not sure if they are exclusive to dell.. but my unpaid bill is with dell.. They call me 10 + times a day, starting at 5:11am on the dot every morning, and sometimes i do pick up and talk to them, have a long pleasant convo. They really need to stop calling so early, i have pictures of them and call logs of them calling at 5, 6, 7 am multiple times and daily! hahah i think it's funny, but now i'm on a witch hunt. Might be gettin that dell bill paid afterall.