Terrible warranty

I purchased the Ellies trolley inverter from Makro on 21 March 2022 for R11000.00. I only had my WiFi and a lamp attached to it. The first 4 to 5 months it’s worked great. Soon after that the batteries lasted about an hour. Eventually they only lasted 9 minutes and was completely flat. I have taken the unit back to Makro and I was told I need to replace both batteries at a cost of R 6000.00. They say they only have a 3 months warranty on the batteries. That is crazy as a car battery has a 2 year warranty. Who in this economy can afford to replace such an expensive item in less than a year. I would NOT recommend anyone to buy any Ellies products as they know load shedding is here to stay.