Ledtronix poor service and bad quality products

I bought am ECCO 3.5kW inverter with two 200Ah 12V batteries as a package deal from Ledtronix. About 4 weeks after installation it seemed that the battery capacity was diminishing. Where I could run my normal loads for more than 4 hours, after 6 weeks the inverter cut out within 20 minutes after a full charge. A simple battery test showed that both batteries lost almost all capacity. When I reported this to Ledtronix, I was told that the batteries were only covered by a 4 week warranty. The owner promised that he will give me very good discount on a lithium battery, even below cost price. The final offer was worthless since I could source the exact same battery for less than the discounted price the offered. From there onward they just ignore my emails and phone calls just leads to empty promises. The sold me a substandard product and now they are unwilling to refund me or to negotiate further. I would steer clear of this business.