Sosolar blames invertor and me for faulty battery

Terrible service, after sending this mail twice, I got a call from some guy at Sosolar, and he proceeded to blame me, for running the battery below 50% ( not actually sure I even did that ) and blame the settings on the invertor ( the invertor has no settings. )

Date: 11 May 2022 at 14:49:57 SAST To: *** Subject: Problem with battery

Hi guys I bought this battery from takelot in august last year . But I didn’t actually use it until November, when we moved into new house We have had about 9 load shedding usages on the battery . Initially the invertor said I’m using 25% load on the battery , and it lasted the 2,5 hours without using any power at all. (Only 25% according to the invertor ) I have a smart tv and a WiFi on the invertor)

Now, it lasts about 30 mins and dies .

I took battery to a battery center to test and they say it’s 85% perfect . So I’m not sure why this is happening .

Take lot refuse to return it

Please help

I’m based in Hermaus WC