We constantly get a phone call from this number: 503-764-4147.  They call three or more time in one hour.   When I call the number back to find out who or what it is, I just get a busy signal.

Called my cell phone and hung up when I answered.

Got a call from 786-228-5784, Sixtel, LLC, MIA.  Caller did not answer - only said "Goodbye" and hung up.  I am on the "do not call list" also.

also received a call from "sixtel, llc, however the number came up as 503-764-4189, wanted to know if i wanted work. WHO ARE THESE PEOPLE?

Just received a call from these people, said hello, then shortly I got a person or recording saying goodbye, this is very irritating.

I received a call from this number as well.  Caller id said sixtel as well.  
The person said she was from GE Securities.  They had called before, I asked to be removed from their list and she was rude and said "we will not do that."  I responded that I was on the DNC list, and that it was a law that if I requested to be removed, they had to remove me.  She hung up on me!

Call from 786 228 5784.  Showed up on Caller ID as "Sixtel LLC, MIA" .  
Picked up the phone, said "Hello" several times but there was no sound on the other end, so I hung up.

I have been on the DNC list for over a year, but after looking at other info about this on the web, I am not surprised to be getting this call.

786 228 5784 reverse phone# search only shows as an unpublished number in Miami Fl.

This calling and then silence seems to be the normal pattern for calls from Sixtel LLC.

"Sixtell LLC MIA" shows up on other numbers in the 786 area code as well as other area codes including 305 (Key West), 440 (Bedford, Ohio) etc.

Judging by the many problem calls that we the public are already experiencing, if you receive a call from this number or company that you are not expecting as a regular customer or client of Sixtell, please report the call.  Here is the official FCC web site to do just that:
http://esupport.fcc.gov/complaints.htm

was a survey about smoke detectors and fire extengquishers in house.

Same here, Sept 20, 1056am just received a call from 786-228-5784.  after saying 'hello' a few time, just hear a beep then, 'goodbye'

received a call from this number: 786-228-5784.  caller ID identified it as sixtel, llc mia. When i said hello a few times, a computer voices says "goodbye."

Same as David. Pretty odd.  If they persist, I'll call Verizon.

Just registered all my numbers w/ DNC Registry. (I know it takes some time to go into effect).

just received a call from this number: 786-228-5784.  caller ID identified it as sixtel, llc mia.  this is at least the second call i've received from them, but when i do answer, all i get is a "goodbye."  i am on the do not call list.