There are ways to block the call on your cell. You also have legal redress in some cases. You can get paid $500 up to around $2500 per call. Also the national do not call list easily found on google. Some may still slip through. Last but not least my favorite and the most effective call the number, identify yourself and request they remove your name. Of they don't seek legal redress.
Calls to my cell with no message left and calls 4 to 5 times a day. I won't answer unless a message is left. If you want me, talk to me. Stop waisting mine and your time!