USAA review: Insurance/customer service

Paid my September insurance bill on 8/4 with my banks online bill pay. On 8/6, my bank showed that payment had been received and accepted by usaa. When I looked at my credit card statement, usaa insurance had charged my credit card for my insurance premium. After being passed through 6 people, I finally spoke to a supervisor who said that they never received the payment and that's why my credit card was charged. If they never received my payment, why charge my credit card a month before the insurance premium was due? None of usaa's excuses makes any logical sense at all.