Mr Price doubling my transaction and refusing to refund

I brought goods on Saturday 19/09/2019 at Garden Route Mall Mr Price. They first did the transaction on that mobile device they have, using my FNB card. The transaction went trough and I received the sms that the money has been deducted from my account. Then the mobile device transferred the transaction to the normal till for some reason. The lady and the floor manager then demanded that I swipe my card again, because they said that the transaction did not go through. I showed them the sms and on my banking app that it has been deducted and that no reversal has taken place. I waited a few minutes and checked again, still no reversal (usually reversals like that happen immediately). Then they demanded again that I swipe my card, because they refused to give my the goods that I bought, even when I showed them the proof of payment on my phone. They swiped my card again and the money was then deducted from my account AGAIN! Only then they gave me the goods.

I went back after an hour or so to show them that there still has not been any reversal. The lady refused to refund me and she also refused to call the bank. She said that she will call them on Monday and she will let me know and then if needed, the money will be reversed into my bank account. I told them that I live 400km away from there and 200km from the neatest Mr Price, so I would not be able to come in again. She assured me that it would not be necessary.

On Monday I heard nothing from them.

Today I called and the lady told me that I need to bring in documentation, which is impossible for me. She then said she does not know what I am going to do now. Still no refund has been made.

I will NEVER buy from Mr Price again !