Disappointed

Cell C costumer care services is really disappointing My phone have been booked countless times due to system always rebooting and will always lose network now January I booked my phone in screen frozen I assisted cause I didn't have insurance and phone warranty was out now the phone came back with no Sim tray inside till today I am assisted cause they its their word against mine they say they return the phone with the Sim tray inside fine I don't want them to replace but I need them to assist me buy a Sim tray for the phone still not assisted with that