What else can I do???

I have had Vodacom accounts for more than ten years, in fact at the moment I have four different Vodacom accounts, mine, my daughter's, a datacard and my son's. Two months ago my son upgraded and transferred his new phone to his own name. At the end of March the increased amount for the new phone was again deducted from my bank account. I immediately went to Brooklyn on the Saturday after pay day. I have seldom in my life been treated worse. the man was so rude that I actually asked him why he felt it necessary to be so rude. Without even asking the details or my account number, he told me, in the door of the shop, that the fact that it was still deducted from my account was due to the fact that the bill was sent before the transaction had changed. I pointed out that this was impossible, as it was already the increased amount that was being deducted. He treated me like a piece of ******** garbage and I retreated thinking that I must be stupid. Lo and behold, tonight the cellphone account that my son had transferred was deducted from my account AGAIN!!! What on earth must I do now??? I am speechless. Please help me.