Do you know that number? Why would you return the calls if you don't? It's inviting trouble to dinner either by getting the wrong person, having to pay a lofty price for the call, and confirming your number works. More often than not, the callers aren't going to use their real numbers to avoid being caught.
Came in as Name Not Found, but I answered anyway just to aggravate some telemarketer. Said he was from Southwest Airlines, they are opening a new center of some kind here in San Antonio and I could get 2 free tickets at absolutely no cost that are good for one year. His accent was so heavy I could barely understand him. Decided I wanted nothing to do with it and hung up.
Same exact set up when they called me. Got passed to a manager. Was told this deal was for a couple, married or significant other. When i said I was single, they hung up on me. Tried to call back and got a recording saying that the call could not be completed as dialed.