A Payment being demanded from me

I was unable to make payments on my vodacom contract due to being out of a job. The consultants hounded me and I let them know what the situation is. In April I received yet another call and advised the consultant to remove my account details as the fact that it kept bouncing meant I paid more money, she neglected to remove the debit order when I asked her to and did it 2 days after the date that it used to go off on, I refuse to pay the R100 that is balancing on my account because I was not the negligent one for that specific month. I paid every penalty fee and also my outstanding bill but did not pay the R100. I have let multiple consultants on the phone and even in the store know that they should s**** the amount off my account or get a supervisor/Manager to call me and this also was not done. Vodacom's service gets worse as time goes by and it makes me very unhappy.