Faulty Device affects childs edu Exams on wa

We have a fauthy device purchased through FNB, have since taken it in twice for repairs now have to take it again for the 3rd time to the Samsung repair center, i have to beg to get it back, when receiving it, it breaks again (lately 3 days later), exactly the same fault, now FNB and FNB Device GURU say no they first have to listen to all the calls, and look and see if the device is actually faulty when it has broken 3 times already. My child is in highschool, exams are coming up and has already lost more than 21days days of work, study notes, class notes etc. I am told take the device in again, FNB ASK THE GDE TO PLEASE POSTPONE THE DATE OF THE EXAMS SO MY CHILD CAN CATCH UP WITH HER WORK AGAIN FOR THE 3RD TIME. BECAUSE OF YOUR BAD SERVICE, LACK OF INTEREST, BECAUSE IT IS TO MUCH WORK FOR YOU AND FNB DEVICE GURU AND SAMSUNG. I HAVE ASKED FOR THIS FAULTY DEVICE TO BE REPLACED - I AM TOLD NO! I GET THE RUN AROUND FROM ONE PERSON TO ANOTHER. HOPE THEY EXPERIENCE THIS WITH THEIR KIDS, THEN LETS SEE THEM MAKE A QUICK PLAN!