Double/triple billing

I am so disappointed with Telkom,it is always double/triple billing. I usually pay via RFT before my debit order date but they still debit and then charge me an extra fee of 200 every single month, I am supposed to pay 199 per month but I end up paying 400 or 600. I am really tired, I have sent a cancellation email because they don't even call or send an sms to communicate with me, I feel like they are just ****ming us with false adverti*****t.