bad service on tablet

I bought a tablet in 2016 for my son it was a Vodafone smart tab for R900 when he started using it the tablet started giving us problems it didn't work on data but worked on Wi-Fi and didn't want to download any games. I took it back to clicks kroonstad in cross street . They told me they will send it away for repairs after a week i got a message saying that the tablet can't be repaired and they will send me a new tablet. when I went to fetch the so called new tablet i got it in bubble wrap they didn't give me a tablet that was still sealed with new serial numbers and in a box. I told the manager that I won't accept the tablet like that and he once again reassured me it was a brand new tablet and if it gave me any problems i can bring it back. after 3 months that so called new tablet gave me problems also it didn't want to charge and just switched off by itself. I took it back to clicks and once again the said they will send it away for repairs. after a week it came back and according to the manager they didn't want to fix the tablet because it had no warranty. I bought the first tablet 17/12/2016 and after it could be fixed received the so called new tablet in bubble wrap in 24/01/2017 . The warranty on the tablet could not have expired if clicks kroonstad did their jobs right and gave me a brand new tablet in a box because the tablet in bubble wrap was send on the wrong serial number to be fixed at that was the first tablets serial numbers and codes on the box. I would really like to solve this matter as soon as possible otherwise I have no choice to hellopeter Vodacom also because if a tablet is under warranty it surely goes to Vodacom repairs to be fixed. this whole mess started at clicks kroonstad who has uncompetent people that work for them ripping people off and not caring about their customer.