Legit law firm doing debt collections. They repeatedly call my cell looking for my ex (from 20 yrs ago) they've always been polite and professional with me. I got tired of repeating myself and telling them that i do NOT know where my ex-husband is, so now i just put them on my "block list".
I love this totally legit app: MR. NUMBER. I use it to block all unwanted calls/texts. Aside from being totally user-friendly, it is also FREE :-)