Vodacom - Pathetic Service and *******

I requested to cancel two numbers I don't use anymore, 30th of July, stating the last bill will be 31 August, guess what, to my surprise, one got cancelled one not, after phoning Vodacom, now they want to cancel that one only end of the month, why must I pay for another month, since I was quoted 31st of August will be the last date, now I must pay for their incompetency, absolutely pathetic. allegedly this has been escalated, but I highly doubt