I found a difference of $2.00
At first I couldn't believe it. I checked my addition several times and then called customer service and spoke with Abby. She ran her own total and agreed that there was a difference of two dollars and immediately told me that she'd issue a credit for the difference AND bring this to the attention of her supervisor. She also agreed to review all the statements I've received in the prior year.
I don't know if the root of this was some kind of internal theft, an error, or what, but my point in posting this is to suggest that it might be worthwhile, at least occasionally to thoroughly review your statements and ask for a clarification if there is anything you don't like or even anything you don't completely understand.
You may discover that everything is all right, but there's also a chance you might find something unusual, just as I did.
I believe that much fraud and identity theft which is so common these days would be nipped in the bud if more people would exercise greater vigilance in their accounts.
If you find any unusual things, or have had special experiences with customer service people in these fields, please comment: I'd be pleased to hear from you.