Overheating solar battery

I bought a solar battery during December 2023. I received it on the 28th of December. With my return from holiday I had the battery installed on the 8th of January 2024. My problems started a week later when I discovered a warning flashing red light. The cells did also overheat. I contacted Ernest immediately who asked me to send the battery back. Courier Guy charged me R405. I received the battery back more or less. 10 days later. Ernest also told me during the waiting time that he forgot to tell them about the fact that the battery was overheating also. The battery worked fine for about a day an a half when the problem started all over again. I informed him immediately about it and demand my money back of a new battery. I also sent him him my account number. According to him they still busy looking at the battery. I spent thus far R810 extra for sending the battery back twice. Please help me.