Refund not paid - Waiting 4 months now

I am absolutely disgusted in Nando's Bryanston service. I placeD an online order on the 7 July and my correct order was not delivered. I have logged a case and called numerous times for feedback on this issue. You leave messages for Nando's Bryanston and they never call back. Eventually after getting hold of them, the manager, Mira, promised me she will send me a voucher. It is end of November now and she still hasnt sent me my voucher after numerous attempts to find out when it will be sent. Absolutely shocked at this service from Nando's. Very unhappy customer!