Door Ringer Purchased 2 Door ringer cameras. Their app will not set up.

I purchased 2 Door Ringer cameras and downloaded their app on my smart phone.  I applied to their server for the security code to be sent to my phone or computer, to connect my cameras to my phone.  It said that there was an error connecdting to their server.

I kept trying for one month, thinking that this is just a temporary situation.  Then I tried to find a support number or email contact.  There is none on-line.  Finally I found a phone number and contacted them. 

They troubleshot the problem on the phone, and could not resolve it, so two weeks ago they said they would mail a return shipping label to me.  Never arrived.  I called the phone number again today, and got an answering machine. 

From all appearances, this company is a scam. I intend to attempt to get VISA to refund my money and charge Door Ringer back.  I just want to warn others that they may not receive a working product for their money.