Su-Kam Inverters — Repeated Service Issue

I have bought a 1000VA inverter from Su-kam, this is third or the forth time that the battery has stopped functioning, i had lodged a complaint on 22nd of April, a person visited on 24th and told us that the battery needs to be replaced, however, till date the same has not been done.
This is a rerepetative issue even the last time the complaint was attended only after the matter was esclated to consumer complaints after lots of follow up.
I guess they are not awre, how difficult is it to manage without electricity in summers. Some serious penelty needs to be imposed as they are not learning from their mistakes.