I suspect that on Amazon's scale, it's probably cheaper for them to toss refunds at customers than to actually fix problems.
Having a first-tier CSR click a dashboard button costs them the 10 cents per month plus 25 cents of labour to pay the guy to read the complaint, find the button, and press it.
Opening a ticket for a well-paid engineer to actually dissect the billing system and figure out where the 10 cent charge comes from, develop a fix, push it through validation and deploy it, probably costs $300.
Having a first-tier CSR click a dashboard button costs them the 10 cents per month plus 25 cents of labour to pay the guy to read the complaint, find the button, and press it.
Opening a ticket for a well-paid engineer to actually dissect the billing system and figure out where the 10 cent charge comes from, develop a fix, push it through validation and deploy it, probably costs $300.