Edcon Ripping Custormer Off

When opening my Edgars acc I was told Edgars no longer opens 6 months acc and only opens 12 months acc. So I opened a 12 month acc. 1. To find out it is lies Edgars does still open 6 month acc 2. I was given overdrafts on my acc that i did not agree to and was not aware of 3. the interest on this acc is ridiculous. My current acc balance is R6119.03 and my monthly instalments are R860. Meaning R509 goes to pay off the acc and the rest is interest at R350 a month. This unacceptable and just as good as *****ing. This is more then the interest i pay on my credit card. I have requested on several occasions that my acc be change to 6month but denied it on numerous occasion. Can you please explain why I cannot convert my acc to 6month as I was given incorrect information by one of your staff members which lead to me opening a 12 month acc instead of a 6month acc.