Discover Bank Account Or Service Complaint

Discover Bank account or service department,

Checking account Problems caused by my funds being low Maryland

I do have a cash back checking account with Discover bank - - - -, UT, -, and the - number is - and the account number is - ). The Discover bank mistakenly input my bill payment amount as of - dollars paid to my Discover Card on - -, 2016. The statement balance of my Discover card is just - dollars. Apparently this transaction is voided. But, Discover bank billpaymnet service provider - tried to withdraw the invalid fund from my cash back checking account with Discover bank twice on - - and -, 2016 without my knowledge, which led to insufficient fee charge of - dollars against my cash back checking account on - -, 2016. I need Discover bank to return the insufficient fund fee charge of - dollars posted to my account on - -, 2016.