How long do i have to wait to get my refund back

I rented a car with Avis for 3 days the calculated the rental for 3 days and i paid it there after the was a holding deposit of R2000.00 extra needed just in case there were some damages to the car of which i also paid and was told will be refunded a day after i returned the car of which i returned Monday the 21.08.2017 and they checked and find out that there were no damages to it but wil only deduct petrol and toll fess money which amounted to R397.00 and was expecting the Deposit of R1603.00 to have been deposited atleast by Saturday the 26.08.2017 but up until today i havent but the funny thing is i received an sms of -397.00 on my account without the refund now my account is sitting with the negative balance which was supposed to have been deducted from the R2000.00 i'm so mad.I spoke to the consultant Nozi who promised to get back to me by today but up until now now 04:07pm nobody has phoned me.