Vodacom debit order

I have been a Vodacom customer for many years and I spend about R2500 with them monthly for my contract. Since 1 November my debit order stopped going off for no good reason and they are sending me messages that they are going to cut my line if I don't pay immediately. I have spend hours on the phone trying to resolve this and every time I am assured that the problem is sorted, but it never is and I don't know who to turn to. This has never happened to me and vodacom makes it impossible to resolve but are quick to give notice of cutting me off. I wish I never signed up with them. Seeing that I have spent well over R100 000 with them over the past couple of years, I would like to send them a invoice for my time spent on sorting their problems out. My rate is R500/hour and I would love to give them some of their own medicine.