Lovisa Overcharged

I visited Lovisa Mall Of The South branch 4 weeks back, after paying for my selected jewellery the cashier mentioned that the payment didn’t go through. I took her word for it and proceed to make the payment again. I mentioned to her that both payments had went off my bank account, she said that it should bounce back and if not I should just call in and they’ll refund my money. I called the store in that same week and was promised assistance, I then went back to the store and left my contact details for the manager to contact me. I have still not heard back from them, after many emails and calls nothing has been done.