Hisense infinity phones

I bought a hisense infinity H76 phone which is defective. Takealot sent it back with no reason. I sent it back due to it being 3,5 months old with barely any battery life. The second time around they say the warranty is void due to visible damage. What about the useless battery problem? I’m prepared to have it fixed by hisense surely that should be an option to assist me? Or am I stuck with a useless phone?