What challenge transaction with a debit card at Jam store Centurion.

I am highly disappointed by how Jam Clothing is handling a card purchase I made yesterday from them. I was paying with my debit card, and their device went off.Money went off my account.The staff would not release the goods that I have paid for because no receipt was generated from their machine.I was then told to wait for an hour the transaction will reverse back to my account.I could not wait there but returned after 3 hours, and showed them no reversal happened, can they give me the paid for goods. I was told to come today with my bank statement. Today, I went to the bank and bank confirmed money is out of my account but the shop must check their side.I returned to the shop, they told me, they cannot check, there is no power. Went back during lunch time, the lady who spoke to me in the morning could not be found.This is really frustrating.I then asked to be given the goods as money is out of my account since yesterday, no reversal has happened. I was given the goods but just now at about 15h15 ,Jam shop phones, they cannot find their money from their side. I have promised to return the goods to the shop but not if money is not back in my account. The business must please upgrade their systems, those speed points used there are most of the time problematic.The staff as well need to be sensive to us as clients, we cannot be running up and down for something one has paid for.Please Jam stores, do something to resolve such problems better.