Last year I owed someone some money and he needed it really quickly so I called up his credit card company, American Express, to pay his bill.
Fast forward to today. I check my bank online and there is an almost 10k ACH pull to this guys Amex account.
When I called Amex then I asked them not to save my info, apparently that did not help.
I called the guy he apologized profusely. I am assuming it was a mistake. However, now I have to wait for my nearly 10k to come back.
Lesson learned. if you need to pay someone do an online bill pay, do not allow them to ach pull from your bank.