Re: one egg in one basket
"I'd still feel pretty pissed off if one of those banks suddenly became unavailable for days on end"
So go into the brick and mortar storefront and demand[0] answers. What's that? Your bank doesn't have a brick and mortar storefront? More fool you.
[0] Hint: Go easy on the "demand" bit ... Going in with a smile, a PleaseAndThankYou[tm], and the attitude of "I don't know if you can help me, let's find out!" when you discover an error helps keep folks on your side ... if you come storming in, looking for blood, you'll only piss 'em off. This is true when dealing with customer service in almost all walks of life. It's basic social engineering, innit.