Discover Card Took money From my bank account and said I agreed...... Internet

Did you set up a payment through the DirectPay on their web site?  I was in your same situation and I choose a fixed payment amount of $150.00.  They took $403.00 from my checking account.  Overdrafted my account and they told me I set it up and agreed to it.  I said " I set a fixed amount of $150.00 not $403.00! "  They said the $403.00 was my minimum amount due and I agreed to it when I set up the fixed amount of $150.00.  They said it says on the web site that they will always take the minimum amount due.  Even though each time I spoke to a representative they all saw the fixed amount of $150.00.  I got an e-mail that $150.00 would be taken out and when I went on the web site it showed a pending payment of $150.00.  But, suddenly the day of the payment it was $403.00.

Thank you Discover Card