Hungry Lion Dishonesty and Refusal to Return Monies Not Theirs

Hungry Lion Somerset Mall told me that my transaction was not approved and made me transct again, when in dact the first was approved. When I asked for my money back they said it would automatically be reversed, it has not been reversed - now three days! Now they want bankstatements and all other stuff to prove it, when the manager at the store saw what happened and was notified and shown at the spot. They say it was a double deduction, which is untrue. I just want my money back, not nonsense.