Cox Returned Payment Fee Policy

Where can i find the current policy on the returned payment fee. I can only find a 2019 residential policy on your site that states a $25 fee. However, $30 seems to be the current fee being charged. Also, why does Cox feel the need to charge their customers this fee. If a customer has insufficient funds when making a payment but still corrects and submits a payment on time; whats the issue? I get writting a bad check, but in todays automatic digital world it just seems unethical. I didnt create an expense of money or time on Cox's behalf. This failed transaction is no different than my card being declined at a store. 

Side note, your customer service reps via chat couldn't find your $30 fee policy.