There should be an Ops Law which applies to both government and business in which a customer or member of public is not deemed to face excessive charging and stacked bills which may lead to bankruptcy and hardships.
The level of blame in the fault should determine how much the business or government must cancel out the debt. So your computers glitch 100% your fault, 100% lost money; if the customer found a way to get free calls or was keeping information from the org then it's over the other way. for big cases like this I'd like to see rulings.
All of this though must be mediated so that bills can not spike, even the tax system is designed to try and prevent tax spikes why can't the laws apply to businesses of services too?