They will continue to call you months, now a year, after you decline their service

I receive this call on my cell-phone.  I don't answer; just "decline" the call.   A call-back on the number took me to "College Works" - it's a painting company that is staffed by college (if you can say that) kids.

Have no clue as to who this is. Shows up as a residential number. Maybe they just called the wrong person?