autopage still deducting even though contract expi

I took a phone on contract,which expired in april 2014, i notified them and vodacom thst i dnt want to renew the contract they kept on deducting different amnt monthly up until now.this is really disappointing,iv escaleted this matter to their managers and still cnt get any explanation for this mess! I want them to refund me the money they have been taking frm may 2014!