4 rings, no message ever left.

i am constantly getting calls from this number! Never a msg left.

Calls frequently, never leaves a message. Called back...some kind of survey company claiming they're not subject to DNC list. Placed on smart phone block list. They added a + sign to their caller id ... now comes up as Turkey. Blocked that one too.

While survey companies are exempt from the DNC, they are also legally obligated to put you on their internal and external do not call lists.  Violating this could result in your suing them under the TCPA law.