over charged

I went to the bank again to downgrade my account from check account to savings as i explained to the manager last time we spoke and was suppose to pay the balance of R340 ,i am still waiting to pay the amount as soon as i get money to because am being overchafged because i am not using the check account ,i cant pay the charges when not using the account.i recently checked my balance via cell phone banking as it is free.the account is charged again..i cannot pay the amaount.