Escrow refund

I have been asked if there is a requirement that a lender has to refund any monies being held in an escrow account to a customer within so many days after the loan is paid off. I can't find anything in RESPA stating this. Am I overlooking it? Could it be a state law?

3500.17(i). You have to provide a short year statement within 60 days from the date of payoff.