Vodacom

I have a contract with Vodacom 4U (Galleria Mall Durban) for my Sony Xperia tablet. The screen display stopped working so I took it back to the store on 22 December 2014 to be repaired under warranty. No feedback from the store so I went in on 7 January 2017. Again, they were confused and after finding the documents made a few calls and promised that I will be contacted in a few days. I called the store regularly and was promised that my tablet will arrive soon. After contacting Vodacom customer care, I finally got a call from the store informing me that my unit arrived from repairs. I went into the store on 12 February 2015 only to find that although my tablet was repaired, my sim card was removed. The store refused to take responsibility for this and I walked away without the tablet after asking them to contact me when they sort out the missing sim. I have since contacted vodacom customercare on numerous occasions and get an automatic replys. I did receive calls from their customer care agents and every one of them said that the store was contacted and will get back to me. I have paid R400/pm December, January, February (due). Vodacom has my tablet - What am I paying for?