CP268 tells you we made changes to your return because we believe there is a miscalculation on your return. You can find the CP or LTR number on the right corner of the letter.You can pay online at Repayment of Overpaid Benefits or mail payment to Georgia Department of Labor, Attn: Overpayment Unit, PO Box 3433, Atlanta, GA 30302. Cashing an erroneous refund check may result in interest due to the IRS. The IRS will send you a CP237A if the tax refund check they sent you was never deposited.