Terrible service

I renewed my contract with Cell C in May 2024. I was charged for Two Tablets i never received. I called them on the 27th the day of November 2024, as i found out from a Cell C representative that i am being charged for the tablets. To my chock and horror i was told to wait 2 days for the investigation to be completed. The 30th of November a lady from their ***** department i guess, called and said i must go get an affidavit from the police station stating i did not get the devices. I told her no. All they have to do is prove to me where i signed for the devices and on which date i received it. We have cameras at work i told the lady so i can go check the cameras as to who received my goods. I asked to speak to a manager when the called was dropped. I called them on the 4th of December only to be told the case is still being investigated. My question: How long am i still to wait on a clear and open case as they did not have stock of the items at the time of my renewing my contract Such a big company. Really terrible. I cant believe i'm being treated this way. No apology in fact i felt as if i was being accused of *****ing the items. Guess what i will do when my contract runs out?