Telkom is *****ing money - Unauthorise service and billing

Account nr: *** I have a Fibre and landline package with Telkom and my monthly billing was R610, my line was 4mb and for the last few month my line was upgraded to 10mb without my consent and just been billed for it but my agreement debit order does not allow more than R610 to be debited monthly and now I am in arears from the time the upgrade was done, this is unacceptable service and day light *******. This is not the kind of service to expect from Telkom this is the reason why we go to other service providers.