“do something until someone is blue in the face” = do something a lot without achieving your goal
“Listen. You can talk to me about the product until you’re blue in the face, but I still won’t buy it.”
“one-track mind” = always thinking about one specific think
“Telemarketers only have a one-track mind: money, money, and more money. They never think about what customers really need.”
Do you feel there should be laws that restrict the hours when telemarketers can call people at home? What do you think of companies that sell your personal information, including your home phone number, to other companies for business (sales) purposes?