Vodacom deducts for product never used or received

We have been loyal customers of Vidacom for more than 10 years, but the service we have been receiving is beyond bad. We tried to cancel a ****le more than 6 times after experation of contract than they still deducted the money.....without us receiving the dingle or using any of the data....R299 for more than 3 months each and every month. We tried getting a tablet for this number seeing that they are already deducting money for nothing....they didn't have any stock but forgot to inform us so another month and another month of R299 for nothing. 8 more calls and still struggling to cancel the tablet. Money still being deducted.....WHO MUST YOU CONTACT TO ACTUALLY GET SOME SERVICE AND FEEDBACK?????? AND OUR MONEY BACK?????????