How can I report them to the ombudsman

When I first received my Wi-Fi router from Telkom no one explained anything to me, it’s a subscription of R249.99 per month. So in July after my data bundles had depleted the Wi-Fi went off as normal, but I pressed a button not knowing what it is for and it now went into what they call "spend Limit" and starting deducting money. By the end of August my bill was R1749, and accepted this charge because it was my mistake for pressing that option. But in July after pressing the button, I called Telkom and asked them to remove the spend limit from my profile so that the account can go back to normal and they assured me that starting from August the spend limit won’t be applicable. But to my surprise, when the bill came at the end of September it said I owed R1666. It means the spend limit was never deactivated as I had requested and Telkom wants me to pay the amount of which it was not my mistake.