Lying customer care

I downgraded my ipad contract to a data contract only on 26 May 2015 at the Mall@reds branch. I was told May month would be the last time I pay the full R389.00. 10 June 2015 I recieved an invoice saying I must pay the whole amount of R389.00. I called customer care on 10 June 2015 at 16:00 and was told I pay for the previous month, the lady at mall@reds didnt explain correctly to me that June will be the last month I pay R389.00. Which I accepted. Today I recieve another invoice and the contract on the ipad is still not rectified. Called customer care now again to query and the lady says she is unable to assist I must call upgrades in the morning. She didnt really have an understanding for the query but I dont understand why I should phone around when voice logs will clearly show The incompetence of the staff in the call centre or the fact I have been **** to while having the conversation is recorded. Im disgusted at the service and seriously considering to cancel all contracts with vodacom with immediate effect without any penalties if its not rectified.