Refusing to refund a failed transaction

Attempted to make a purchase online, Transaction Declined however the money still went out my bank account. (3X R 9999.00 total R29 997)

I contacted Builders requesting a refund, Ive sent them my bank statement showing the transactions.

They refusing to give me a refund stating they need a POP, and they cant find the funds on their side (they not seen the transactions). What Other POP can I give them on a transaction that failed??? They want me to give them an invoice from the bank etc. The bank Doesn't have anything else besides a statement.

I've even gone to the extent of giving the exact time the transaction was done.

Im now out of options, all I want is my money back.