No Feedback, No Response, No Invoice produced and no refund! Useless!

Last week I hired a car at Tempest Car Hire via Sanlam Reality, collected it at Europcar since their offices are ultimately closed in East London. I collected the car on Thursday afternoon and returned it on Saturday after. They usually take a day and then they would process my invoice and send me back my refund, and today it's Tuesday and still no word. I called all their call centre numbers and 043 landlines and yet no one was able to assist or even remotely pick up the phones. This is utterly unacceptable service!!!