STOP payment fee for a check that USAA failed to ensure was delivered?

Beware, USAA bill pay users! My mortgage payment that I have paid through Billpay for 7 years didn't arrive at my mortgage provider. I pay early, so I wasn't too concerned but I called USAA anyway and was given the proverbial "the check's in the mail." A week later, the check STILL hadn't processed, I called the mortgage provider who claimed it hadn't arrived, and I called USAA to stop payment. They wanted to charge me $29 to stop payment! I kid you not, $29 to stop payment for a check that should have been transmitted electronically in the first place (bank to bank in the mail? Seriously?). USAA wouldn't buy it for a second if I missed a bill payment because the "check got lost," and now they don't stand behind their own process of paying bills? I've complained for ten years about USAA's declining service and threatened to move all of my assets, I think the time is now!