Extremely bad service Cashbuild

I bought an item at Cashbuild Springs - when I was paying the cashier said the payment didn't go through She put it through again. I checked my bank account and the amount was deducted twice. I went back and was told that it will be back into my account the next day. It wasn't in my account the next day - then they want a bank statement ect which I provided. Totally unnessacary all the paperwork that they asked from me. After 7 days I haven't got my money back. The manager as well as head office have an attitude and expect me to be happy whenever I get my money back.