Telkom poor communication

My wife is having a router with Telkom, they agreed to debit R199,00 from her account every month.one month they debited R469,00 she saw on the statement that they are going to debit R490,00 in the next month.when she go to their shops they didn't know what it was happening. They made a request to Telkom to phone her of which they phoned. The phone cut before they even explain what was going on, they never phone again.All they do was to debit the amount of R490,00. We reversed the amount, now they cut the service,no phone call to explain what this amount is for.