Please setup billing alerts, know what your daily spend should be, add a little for if things grow a little unexpectedly. But you should absolutely be getting alerts if your spend is out of the ordinary for > 2 hours.
Apart from that you seem to be limited to monitoring individual resources, or using some external service that enunerates everything
Disclaimer: I work on AWS, although nowhere near billing
It's amazing what I can have a pre-paid account for a VPS hosting in Nicaragua, yet Amazon doesn't have this as an option.
/rant
Or, you know, price it in and do your own risk estimates to make this a seemless experience, but AWS got away with not offering anything, so I'm already assuming you want to be passing all the cost to the customer (heck, amazon, if you are reading this, you can even skim a little bit of the "insurance" money! )
Why any e-mail provider doesn't delete my account if the payment weren't received in time?
Why AWS/Az should outright delete my services as soon as the money on my pre-paid account hit $0?
> Storage costs money too, simply shutting down the services won't quite cut it.
Until you give AWS/Az $B in storage costs it costs nothing for them to store your measly couple of TBs of data for a month, till you sort out your money situation.
And to give you a perspective on the situation: I have a service in AWS. Every month AWS sends me tons of letters of how it can't charge me for the service, how this can lead to a service cancelling, what should immediately run and punch in a working card to the account or else.
The thing is what the cost of the service is ... $0.51/month. For $6 I could've had a year of nag-free service, for $60 I could've had a 10 years of nag-free service. I would happily thew not even $60, but $100 to AWS so I could just forget it about it, instead they spend more resources trying to charge me every month and sending me all those scary letters.
> complex cloud services are not.
There is absolutely nothing what would prevent something to alert you (or disable, if you wish so!) if your current spending is 5x or 10x of your previous month. In OP's situation this is 66x difference.