Terrible Service!!

It will now be 6 months that Vodacom has my tablet for repairs!! The manager at Newcastle mall was very helpful and went out of his way to help me but head office and the repair centre are just terrible at what they do!! Promises upon promises and still nothing. I have a lenovo 10.1 inch tablet which gave problems so booked it in for repairs 6 months ago. It came back twice NOT REPAIRED!!! Now vodacom is still dragging their feet and excuses but no tablet! I am paying for something for almost 6 months although it was under warranty!! Is this how a huge company behaves?? Once they sell u something their after service stinks!! Will i get a refund for all those months? Will i get a new tablet? This is breach of contract!!! Come on Vodacom.. treat your customers with the respect they deserve!! You guys are getting worse!! Will definitely go to mtn from now!! U guys are pathetic to say the least!! U make me pay for 6 months for something i dont have or can use. I will take it up further and even social media!