One of the smallest things I can see is a decimal point. It is way too tiny to cause so much trouble. I was paying bills online, and one of them hopped around a bit. Instead of paying Progress Energy, (the electric company) $167.00, they actually got $1670.00. And they won't give it back.
I caught the mistake the next day, October 15th, over a month ago, and called them up. Yes, there it was, the polite lady from customer service agreed. She promised that they would order a check back to me right away. Of course I believed her, but I transferred money from savings just in case her version of right away was not the same as mine. After a strong letter and two more phone calls, all that has come in the mail is an overdue bill, including a finance charge. So they have not returned my money or used some of it to pay the bill. One more call.
This time she told me that the refund check had been ordered October 23rd from the company that actually writes their checks. That company takes several weeks to write the checks because they need to verify that there is money in the account. This strains the imagination, to think that Progress Energy's finances are so questionable that their check-writing company has to run an audit before cutting a check. And I know they have at least $1670.00.