Telkom getting money from me at all costs

I am a very disappointed and unhappy customer of Telkom . I took a contract with them a couple of months ago. While I was being offered this contact I told the consultant that I get paid on the 25 of every month. He said my first debit orders would be on the 30 but from then on wards would be on the 25. That was our agreement. But Telkom has been debuting when ever they feel like it. In February I thought finally their doing things right , their debit order was on the 25 February then suprises in March they decided to debit on the 30. Of course by then I didn't have money but I guess that's what they wanted so they charge interest. I mean why in God's name would they debit on the 30 when I get paid on the 25. They don't care about me as a customer all the care about is making money out of me . They don't care how their selfish act affects me. All they care about is Money