Customer Care rude and unhelpful

I cancelled data contract in Feb. Received a ridiculous bill of over R4000 to be debited in March, but I was told they would deduct the total outstanding amount in order to close my contract. I then received another bill of almost R6000 to be debited in April. My average bill was always in region of R2000. Strangely it was the bill for Jan and Feb. I only started work mid January and February is still a very quiet month so it would be impossible for my account to be more than double normal usage. I contacted customer care to query and request itemised billing for months Nov to Feb so that I can see the cause of inflation. I was transferred back and forth between consultants, eventually being assisted by someone who knew how to deal with my query. I was told I would have to wait a while because my number was now cancelled. I eventually received itemised billing for my active number. Went to vodacom and the consultant got a guy Samuel who dealt with my query to call me back. Samuel was extremely rude and eventually sent invoices and not itemised billing. This back and forth has been going on since March. All I want is to see why my bill was so high while being inactive.