Terrible service all departments

My contract expired on 17 July 2015. When I spoke to cancellations back in May & June to give my cancellation notice to end the contract when it expires in July. I received a sms on the 30 July to inform me my unused minutes and data will be disconnected on 31 July. On the 1st August my account got debited with R328. My account was also debited the exact same amount on 1 July. My contract has been switched to prepaid and despite me phoning various call and financial centres no one wants to help me resolve the issue. Today I have been told by accounts that they cannot see totals or activity on my contract because my number is now prepaid. Vodacom cannot keep *****ing people's money just because they have my banking details. I expect a full refund and a competent representative from Vodacom to resolve this issue.