Who called from 3021217617

The caller ID said " INVALID NUMBER " who answers that??? , not me. They left no message.

Received call @ 0700am this morning,  claims to be 'Medicare Verification Dept'  -  Scam

Received call at 0733 claiming to be Medicare verification.  Had my address, phone number, as well as how I am listed with Medicare.  I said something is not right about this and she stated she was having a hard time hearing me and would call back.

Called at 6:02 am, rang twice, hung up, I blocked the number

didn't say anything