Some scammer trying to threaten/harass you by saying they are a debt collection agency. They use your publicly available information like name and address and try to collect more personal information like date of birth and ssn under the pretense of authentication. Be cautious while dealing with these scammers.
This number calls at different times of day, lets the phone ring twice then hangs up. No message is ever left. No name comes across caller ID
If you have a Genesis or Milestone credit card, they are calling about your payment. They don't call unless your card payment is past due. Just answer or call them back to arrange payment or they will keep calling.