Focus Aquatics refusing to refund deposit

At the end of January 2018 we paid the owner of Focus Aquatics, Storm Arnold, a deposit of R9000 to install a water tank system at our property. More than 3 months later he still has not completed the job. All he did was lay down a slab which turns out to be too small for the tank that was meant to be installed, dug up the garden, removed bricks from our paving and we have an unfinished electric installation.

Storm advised that he couldn't complete the job but he also refuses to give back our money. We have given him 2 months to pay us back but he still hasn't and simply refuses to refund the deposit.