Discover Credit Card Complaint

Discover Credit card department,

Payoff process Alabama

I forwarded a payment to pay off my Discover credit card. It was received by the due date. When I received my credit card bill, instead of it being paid off, they listed an additional interest charge. I called them and they said that was interest from the previous billing cycle. I believe this is a purposely fraudulent practice by Discover. I should not have to call them to get a pay off. Their statement should tell me the date interest is charged and what it was calculated on. It should be listed on the statement for the period on which it is calculated. In the end, they are refunding the interest, but I would like for them to be investigated. All other credit cards I use do not use their practice. If interest is charged, it appears on the current statement for the period they are charging for. No one should have to call a credit card company to find out their payoff. How many other innocent consumers are paying additional interest that they should not be paying?