I would say one of the many dam sportsbooks ive played with over the years sold it to em...Ive been doing this so long it doesnt suprise me that my number is out there somehow...a lot of these cappers seem to be in business to put out picks to help balance the books money on games...
More than likely a employee of a book sold your info I bet, you gotta remember these guys don't make a lot of money and get offers all the time from scammers to sell a copy of the data base of the book they work at.
You can find all kinds of data base offers at forums that cater to affiliates for casinos, poker rooms etc.
I always use my phone # as 555 - 1212 let them cold call directory assistance. ;D
No reason for any book to have you real number I think