Please help

Im so dissapointed i bought a hisense E 40 on the 2 march 2021 after 3 days the phone was giving me problem i went back to pep with the intentions of returning but the mananger assisted me and gave me new memory card i told her the phone has a problem when charging it does not get full fast she then told me is bcz is new i bilieved her and went home after 7 days it became worse when u charge it it says it will be full after 20 hours and it was even not easy to charge it it looks like both battery and charging system has a problem,so i took to it pep so i wanted help i cant cope without a phone it has been 2 weeks know can they give me another phone since i did report the matter while still early with intention of changing it but the lady convince me it will be fine??