I'm pretty sure it would be illegal to do that in the EU without some explicit big red "You are about to overuse your quota. Any additional storage used will be billed at x€/GB. Do you want to proceed?" warning message.
Data Hoarder
We are digital librarians. Among us are represented the various reasons to keep data -- legal requirements, competitive requirements, uncertainty of permanence of cloud services, distaste for transmitting your data externally (e.g. government or corporate espionage), cultural and familial archivists, internet collapse preppers, and people who do it themselves so they're sure it's done right. Everyone has their reasons for curating the data they have decided to keep (either forever or For A Damn Long Time (tm) ). Along the way we have sought out like-minded individuals to exchange strategies, war stories, and cautionary tales of failures.
There were messages from iDrive coming in by mail, but no question or even better an automated sync stop before confirmation. Unfortunately these mails were automatic sorted so that I didn't get them in time.
I guess it's part of their business model where they earn quite a lot of money even they lost me as customer. It was similar in Europe with mobile plans, where they charged you whatever they wanted until it was capped to a max of 60 €/month.
At least I learned out of that, that I have to be more careful with some things.
Based on the "no interest for X months" credit model by the sound of it. If that loan isn't paid off before a certain date, they get you on some stupid high interest rate for the entire amount & duration.
They're 100% betting users will over run because that's what they do.
I don't use iDrive. Does the service/application inform the user that they're over quota, or close to it- or does it quietly over run?