It is a simple process but it will require you to make a trip to the bank, I just did this last week. Your bank will have to print off an unauthorized ach form, you will fill in a few quick items, sign it and the money should be back into your account in a few days. You will also want to put a stop on any future ach activity from the lender, they are known to continue even after you do the first dispute, so nip it in the butt on your first visit to your bank. goodluck.