Overcharged and missing item

I've placed an order with Checkers on the Sixty60 app. All items were in stock the amount of R332.99 were reserved on my bank account. When the groceries were delivered I received only 2 items and R356.92 went off my bank account. I've contacted them twice with no luck, I've logged tickets no luck. Eventually I spoke to Siyabonga one of their agents 6 days ago and on his side he could see that reserved amount and asked me to forward bank statements which I did. He also advised to wait a day and then check my bank again to see if money owed to me was reversed. No money was reversed I've been emailing him with no response. When it comes to delivering groceries on time u get 4 stars but with regards to solving customer queries I rate you 1. PnP asap are slow in delivery but customer service are phenomenal. I want my money back, and I won't make use of this service