debited my account when my contract is cancelled

Vodacom cancelled my contract without my permission they was supposed to cancel it on the 31st of July however they cancelled it on the 23rd I have paid Vodacom off coz I'm sick and tired of them now they debited my account when my sim card is pre paid and the manager moosa based in Johannesburg is so Unprofessional it's not even funny I just want my money back in my account and nobody wants to help me.