Invoice and deposit refund enquiry

I rented a car at Thrifty EL Airport on 20-22 of August. Upon returning the car I requested for an invoice. The gentleman assisting me confirmed my e-mail adress and said it will be sent via e-mail the following day. However, I am still waiting. I called today (friday) at 17h30 and the lady answering the phone said that the accounts department is closed I must call again on Monday. If it takes this long for a mere invoice, how long is it going to take to get my deposit refund back? Please assist