Top up removed - big bill - shocking service

In October I upgraded my data contract and do not recall being told on the upgrade call that the top up was removed from my account. At the end of November I received a huge data bill as I did not know the top up was removed and so the data did not stop when my cap was received. I phoned on 2 Dec as soon as I got the bill to query this and to have the top up added back to my contract. I have been pushed from pillar to post and have not once had a phone call from Autopage with feedback on this issue. I have phoned twice more - the first time on the 4 Dec to be told that the query was closed as this was an open line when I asked whether the upgrade call was reviewed I was transferred to someone else who told me that was wrong and the query was open and they would request that the call be reviewed. I had no response so called again today and have been through a similar experience. I have also requested to be sent the call which I can't do but can review at my closest branch. They gave me a number to call Tokai branch to do this which doesn't work. I would like a senior person to pick this up. The service is so poor I have spoken to 7 people since the start of this.