Santander Bank US Bank Account Or Service Complaint

Santander Bank US Bank account or service department,

Checking account Problems caused by my funds being low Rhode Island

I messed up a payment and needed to use my overdraft protection for my Santander checking account. I was on vacation at the time, and as soon as I returned went to Santander Bank and paid it off. Since it was a Santander bank and - accounts were Santander. I paid it off in full. i then noticed on line that there was a balance on the credit line. I called the - # and got nowhere in resolving this. I then went to the branch where i made the payment. They told me that the balance was interest that accrued because it took two days to clear. I find that totally unacceptable, since I took money from my SANTANDER checking account to pay a SANTANDER bill at a SANTANDER branch.