calling my phone

they called my phone for a week in the day time when i work. finally i am tired of them calling so i called the number to see who it is. I hear firstsource advantage. he said he is looking for this gomez guy. i don't know who this is or how they got my number. he wouldn't tell me why they wanted gomez just that he gave my number as his number. who are these people. now i have to get a new phone number and have it unlisted! dam him and this company!!!!!