866-216-6235

Received a call claiming they were from my credit card company.  The telephone number did not match the phone number on the back of my card.  I called the official credit card number and they told me my account was okay.

Got a call from this number. It was from Citi Credit Monitor service. I believe it's legit.

same number. did not answer.

Just got a call with a VM claiming that "The City" had sent materials that the post office had returned and they told me to call this number back for "Verification." Sounds very suspicious to me.

I received a call from 866-216-6235 an automated message claiming to be City ID Monitoring and told me that I have a returned package.  The service tried to transfer me to a verification specialist but none was available and told me to call another number to reach the specialist.  I then hung up before the number was given to me.  I didn't order any packages from anywhere or anyone.  It is a SCAM.

Yes, it is Citi Bank credit/ID monitor services.  If you have submitted a request to pull your credit report(s) or if u signed up for card protection this is why they are calling you.  
After the 1st free month they will start charging you so, watch out for that.

I recieved a letter in the postal mail offering services from 'Identity Guard' with this contact number: 1-866-216-6235 and website: https://app.identityguard.com Is this truely the number and website for the legitimate ID protection service called 'Identity Guard'?