Disgusting service from Vodacom

I have been trying to cancel my quote and have been messed around by the cancellations department for over a week now. I was sent a quote for the cancellation which is almost exactly the amount I have left on my contract. I have 4 months left to settle. They profess to charging 75% of the outstanding amount, but they are basically charging 100%. No one can explain to me the quotation amount or the calculation to get to that amount. They keep sending me to dead ends. One of the call operators said I must email ***. The email provided cannot receive emails or simply does not exist. I have never dealt with this level of incompetence. I have been a loyal customer for 15 years and this is the service I get. I am disgusted and I just want this simply matter sorted out