Complaint for builders northmead benoni

I would to bring my concerns to attention of the store manager at builders warehouse northmead, i was in your shop on Saturday to purchase a simple product no more nails while busy paying your system crashed and could not print a slip, the money has gone off my bank account and I proved this and still was not allowed to leave with what I came to buy, three days later I still don't have my money back or my product I purchased, I was made to feel like a ******** and my privacy invade by having to continually show the lady who was busy with this my bank account, I was called on Sunday to advise the amount was not in builders account and they would check on Monday, its now Tuesday no phone call no refund of my money i spent and no product I paid for this is absolutely disgusting..