Double ECHECK/EFT RETURN FEE

On Feb 4th, I received an email from xfinity that my bank payment was returned and therefore will result in return fee. At that time, my bank account had no problem paying the regular charge and no transaction attempt is found in my bank transaction history on Feb 4th. I doubt if the return is on my fault or xfinity system failing to making the proper attempt to get the payment.

In result, I was charged two ECHECK/EFT RETURN payment of 39.99 in my bill statement for the last billing date. Firstly, I don't understand why it charges 39.99 instead of 25 as stated in the policy. Secondly, why is it charged twice? 

On the website, I was told to pay for the charge asap to avoid losing internet, so I was forced to pay 119.97 at that moment and I did that. That's a ridiculous amount.

Lastly, I just checked my current billing statement which is scheduled to be auto paid on March 7th and it contains regular monthly charge + double ECHECK/EFT RETURN Fees ($25 * 2). This is absurd. Xfinity made a mistake, not even making a payment attempt to my bank account and claim it to be returned from the bank. Then, it charged me two ECHECK/EFT RETURN $39.99 each in the previous month and two ECHECK/EFT RETURN FEEs $25 each in the current month.

If this is not fixed promptly, I'll have to take some actions to properly address the issue.