Worst Service from Solar Power Energy or Power System Energy PTY

I paid Solar Power Energy or Power System Energy PTY an amount of R15 495.00 for a 7.2kW Lithium-ion Solar Battery on the 27th of November 2021 that was supposedly on special on their website http://www.powersystemenergy.co.za/. I have not received my battery since and all I'm getting are excuses. I've been demanding that they refund me as it seems that they sold me a battery they don't have. A guy called Denis keeps sending me one line emails with broken English making promises he hasn't kept. Another one called Derik is also giving me excuses and has just told me that they'll deliver the battery when they receive stock despite the fact that I've demanded a refund. This is the worst service I've ever received and their refusal to refund me will be reported to the authorities.