ATLANTIC CITY, N.J. – New Jersey's top gambling regulator is threatening to fine sports books operating in his state that ask customers to cancel requests to cash out money from their accounts, saying the practice is ongoing and “unacceptable.”In some cases, sports books have offered to give players cash bonuses if they cancel withdrawal requests, according to David Rebuck, director of the New Jersey Division of Gaming Enforcement.In a letter posted Wednesday to the division's website, Rebuck did not name the sports books who have engaged in this practice, nor did he say how many complaints the division has received of such activity.But he wrote that trying to talk customers out of withdrawing funds from their accounts violates numerous.