Service disappointing

I rented a vehicle on 18-22 July from Avis Amanzimtoti , I paid my deposit and rental fee as per quote. on the 20th , i returned the car, clean , without a scratch. on the 21st, i got a call that the board was removed, i checked with my family, and indeed they accidentally removed the board. i returned the board the next day 22nd. today the 13th August, I'm still waiting for the refund . i have been calling daily to enquire, i am directed to other departments without assistance. Rental reference : E- ***.