Standard Bank vs Bredell Spar

Duplicated transaction On the 3rd of July we make a purchase at Bredell Spar Groceries - R823.21 Withdrawn cash the same time for the amount of R500.00 (Total amount of slip is R1323.21) When I checked my bank statement the next day total amount of R1323.21 (outstanding card authorisation) and another amount of R500.00 was deducted from our account in total amount deducted on my bank account was R1823.21 I visited Spar on the 5th of July to show them that R500.00 was twice deducted from my account. They checked their books and found only the R1323.21 not the extra R500.00 I went to Standard Bank on the 6th of July and they said that this will be rectified when authorisation on their side was done. They told me the reason why the R500.00 was also deducted on the 3rd of July because it was a cash transaction at the till. According to them the amount will be rectified at their head office with the amount of R823.21 When I checked my bank statement on the 9th of July they did removed the R1323.21 and replaced it with R823.00 and then the deducted also another R500.00 I went to Standard Bank on the 13th of July and they told me that they cant reverse the R500.00 because it was allready paid in Bredell Spar's account. They sent me back to Spar to rectified it with them. I visited Bredell Spar on the same day and they promised me to look into it. On the 17th of July Spar's account manager phoned me and told me that they haven't received the R500.00 (6 July) only the R500.00 of the 3rd of July. The lady told me that she phoned Standard bank and they said the amount on their side not duplicated. This duplicated amount was deducted on my bank statement. The bank told me to fill in "chargeback customer, statement of dispute" According to them it would take up to 60 days to be resolved and they cant promised that we will receive the money back. Now I want to know what happened to the second R500.00 that was deducted from my bank account and nobody (not Bredell Spar nor Standard Bank) can give me any answers. What can I do to resolve this matter as soon as possible?