Duplicate Transaction due to the banks error

Duplicated transaction appeared on my statement for over R1600 purchase from Makro. Twice it's come out of my account but my Makro receipt clearly only shows it being debited once. Phoned FnB and they said it was an error they were aware of but still a day later and my funds aren't available nor the transaction reversed. It's bizarre to me how they can't fix their own banking error in their own time but at least reverse the transaction which is clearly incorrect for the same exact amount down to the cent appearing at the same time on my statement. - it's unfair my balance isn't available!