It's the WCA Offer Clearing House. If you call the number they called from you reach an automated service that allows you to remove your number from their calling list.
GOOD LUCK WITH GETTING YOUR NUMBER REMOVED FROM THEIR LIST
ALL THEY ARE DOING IS PHISHING FOR ACTIVE CELL PHONE NUMBERS
THAT THEY CAN SELL.
YOU WERE HOOKED WHEN YOU EITHER ANSWERED OR CALLED BACK
;-(