Con artists

I went to apply for a new bank card and was offered the Standard bank.sim card. I declined but seeing the consultant was such a good **** I ended up being fooled into signing up for it. She told me you get R110 free airtime every month so the airtime would exceed the cost. Next thing I hear on an advert on television is that this offer only applies for the first three months. Then I was told it is only R54 a month but I was charged R68. How do I cancel this sim card?

Over and above all this, I took the option of the MyMo current account with a once off monthly fee because I was convinced by the same consultant that this monthly fee of R110 covers all transactions; however, I am being charged bank fees almost daily!