Feeling cheated

I am extremely disappointed with my recent experience with Vodacom. I migrated from one cellphone package to another and was more than willing to pay the migration fee of R4400. In the quote it clearly states that this amount included VAT. I have 3 accounts with Vodacom, i.e. for my cellphone, fiber and wifi router. My frustration emerged when I noticed that my bill for last month included these accounts as well as the migration fee with VAT calculated AGAIN on the TOTAL amount. I queried this with customer care who took 2 weeks to get back to me, only to find out that they had made no chages and found the statement to be correct. I then sent a very angry email, and have been completely ignored since. I feel like I have been cheated by this company that I have been supporting for so long. If it were a measly amount of money I wouldnt be bothered but the amount of VAT thats been additionally charged actually works out to R660??? If it were a simple mistake, an apology and a refund would have been acceptable. But the fact that this has been queried yet still not resolved makes me feel as if I am being taken for a fool!! I cant wait for these contracts to end so that I can jump ship, and not have to deal with this incompetence again.