Device faulty

Ackermans Connect Daveyton I'm not happy at all, February 14th I bought a phone Premio X84 only to find after the 7 days I was given to exchange or refund the phone if it gives me problems that it's actually faulty when I turn the phone on there's something inside the screen that's moving the phone turns off at 15% battery also has network problems I don't even remember how many times I bought data without using it because the phone doesn't wanna connect to the network I've tried all the networks but that didn't help I'm a student I bought this phone for school work (online learning) but it's not helping me at all I'm far behind with school work, I would have loved for the phone to be booked in so it can be fixed but time is what I don't have, I can't wait that long. I'm really struggling.