Mtn contract

On the 13th of April 2015 I went into MTN Northgate Mall for my contract upgrade. I was helped by a gentleman name Lebohang. I have been on a top up plan for the 4 years (this being my second upgrade). I did not want my plan to change and I explained this to Lebohang. He mentioned that all that was changing on my plan was the airtime I used to get at Rand value was now changing to airtime and when this was finished I could of course top up my account by effect of buying airtime or data. I confirmed with him if my debit order would be at the consistent am out it has been for my previous for years that I have been with MTN and hus answer was yes, nothing will change merely the minutes and amount of data received.<br> <br> Now, I find myself with a bill from MTN that is way beyond what I was signing up for. How is this possible? The customer care number is unavailable due to the on going strike. I finally got a chance to go into an MTN store in Elridge Centre on the 17th of June 2015 and they could not help me and redirected me to Northgate. The lady assisting me mentioned that Lebohang from Northgate changed my plan to normal billing and he should have offered to give me a limit on my billin