OR do not get their money automatically. They charge the provider, who when charged generally pass it on to the customer.
Providers are entitled to challenge the charge, but some seem never to bother unless the customer gets really stroppy, some fight back two or three times but cannot keep it up, often for good reason, sometimes without good reason.
AAISP just refuse to sign off the job, and refuse to pay up. They stick at it when there is clearly something that ought to be fixed and is provable.
Part of the issue is that CPE faults are common; for a typical ISP, if you assume that it's CPE or extension wiring, and act accordingly, you're going to be right more often than you're wrong. Further, it's hard to tell from basic RAIDUS logging (of the sort you'd get from a Cisco or Juniper LNS) whether the customer has simply rebooted their CPE, or whether they've also done the wiring change you've asked them to try.
AAISP's monitoring makes it easier for them to distinguish common CPE or extension wiring faults from network faults, and thus swings that calculus the other way - they can tell that you're not doing what you were asked to do, and react accordingly, and thus when they do refer a fault to their supplier, they're able to be confident that it is a network fault.
Oh, and their ability to exploit their highly technical customer subset is also helpful - how many ISPs would be able to (e.g.) get their customers to dump Ethernet frames on an interesting subset of lines and see if there's a pattern to a failure? Or stand up iperf servers for an interesting bit of speed testing? That enables AAISP to track hard faults.