unwanted call... no voicemail

they called me yesterday from this number and left no message. today they called me from this number 559-226-9349
one number off.
still left no voice mail.

it is nichols research in fresno. a focus group and market research company that pays you between $75-$200 for your opinions etc. i signed up for their database, so it is not an unwanted telemarketer call.

but for the love of corn, why cant they leave a damn message.