Fed up Vodacom Customer

I have a router contract with Vodacom of which the agreement was R350 a month. But for quite sometime now they've been debiting any amount they wana debit. In September they debited R 1350 and this month R659. I've reported this before and they said they've sorted it out. But still same problem again.

I have contracts with other Cellphone networks for years now but I've never experienced this. I'm really fed up with they scheming 😡😠!