Sol-Terra bad service

I purchased solar from Sol-Terra and they did the install of almost R100 000. I have 10 years warranty on the items and the battery stopped working after 2 years, the installer ***ner of company) came out to my house on 3 different occasions but could not resolve the issue with the battery and also on 3 different occasions could not find issues at my home like water damage as the install is done in a locked garage, sol-terra then removed my battery and send it off for repairs - during this process they decided to use wet boxes to transport the battery to the repairer, the owner of sol-terra admitted in whatsapp messages and whatsapp voice notes that he used wet boxes to transport the battery in. When the battery reached the repairer they noticed the wet boxes and took pictures of it and sent it to sol-terra and myself, they then went ahead and charged me R8000 for repairs and the 10 year warranty is void due to sol-terra using wet boxes to transport this device in. They are refusing to refund me my money