Do not answer unknown calls and do not call them back. If you continue to answer they will continue to call. I would not worry about who is calling. What I would do is consider getting a call blocker. They're available on line and start around $40. http://800notes.com/nb/search?q=call+blockers
I've been receiving calls from this number the last 2 weeks. They either hang up, or there is no one there. Very annoying and I can't find out who is making these unwanted calls.
Do not answer unknown calls and do not call them back. If you continue to answer they will continue to call. I would not worry about who is calling. What I would do is consider getting a call blocker. They're available on line and start around $40. http://800notes.com/nb/search?q=call+blockers