Please help

I'm with Vodacom contract they refuse to cancel the contract when I call them they say I should do 30 days notice,which I did on the march 1 then they say I will be charged because my contract ends on April then to avoid charges did notify on the 27 March as they say the lady said to me it will be my last debit order also she quoted that I won't pay she send me a quote via email also now end of the month they debited from my account off which I knew that it will be my last debit order what suprice me they say I'm owing again of which I can't afford please also that number I reported that is ****** I don't have even that sim card help my email *** .