I got a missed call from this number tried to call back and it said this code is invalid. I really wish they would stop calling me especially when I'm at work

Well this one was truly priceless!  I've been getting calls for the past few days from this number, but this time, they left a message:  There's no sound except someone breathing for a while, then he says "Okay.  Yes. Right".  I don't know who he was talking to, becasue there's nobody else's voice on the line that I could hear.  Then he said something that sounded like "Cum-boy-in."  I'm sure that wasn't the actual word, but it sounded foreign and I couldn't make it out, so that's the phonetic sound of it.  From his tone, I think it was a farewell greeting, because he hung up after that.  However, the recording continued with only someone's breathing on the line for several seconds after that.  So strange!  Now they're talking to themselves!  LOL