Unauthorized purchase.

Money got deducted from my bank account, basically an unauthorized purchase for R678.67 on 04 August 2019. I contacted Capitec immediately to stop my card and went into the bank to change my details and was told I won't get my money back. I was told that it takes 14 days for the investigation process and it is 22 August 2019 and I am still waiting!!!! I called in yesterday to find out what is going on and I was told it takes 30 days. All I want is my money back because the customer service is ridiculous. I am even thinking of changing banks. Please help, TIA.