Hisense T5 Pro (Battery Life and software Sucks!)

I am so disappointed, Three months ago i bought a Hisense T5 Pro Cellphone from Foshini in Kennilworth Centre Cape Town to my surprise the phone the phone first started off very slow hanging on apps like WhatsApp and Facebook, then the occasional freeze and a week or two ago the phone started to switch off right after i fully charged it to 100%. This is unacceptable as i now own it for three months so i cannot even take it back to the store were i purchased it from as the store has a 30 day return policy. My question to Hisense SA is this why was the phone not pulled from the market after numerous complaints were lodged from consumers if i look at the review the phone got on Hello Peter people have been complaining since 2018. I need answers and a solution from Hisense as to what i can do to have this problem fixed.