No refund, no feedback for a faulty Inverter

I purchased a Mecer hybrid solar inverter from Makro on 2 February 2023, it was delivered to me on 8 Feb and I had it installed by a certified and accredited installer on 11 February. Unfortunately, the inverter was faulty from day 1, as it kept tripping. It had to be uninstalled. I logged a return for the faulty unit on 12 February and my request has been ignored. I have phoned Makro countless times and feedback is the same everyday, "they will get back to me". Please I need this unit returned and my money refunded urgently.