get hang up calls from this number caller i. d. only says unassigned

Caller said " this is the return call about the back brace you called about". I never called them so I just hung up. Caller ID read unassigned.

Thieves call you up and convince you to give them your medicare number (social security number). Then they send you a back thing you will never use. Medicare will not pay them. You are stupid if fall you for this. Hang up when you did not call them, and they ask for your info.