Yup. But if people had half a brain, you would disable services properly before leaving the service.
When you hire a web hosting company, and no longer wish to have their services, do you just stop paying the bill or do you first transfer all your web data to the new host first, shut down the existing host services (db and web), remove all the content, and then close your account?
I mean, I don't fault her for being upset, but people can't be ignorant against technology either just because marketing department says "It just works".
The act of leaving should be enough. This isn't anything like transferring a web host. Consumers should not be expected to disable individual services before switching to another... especially one that's supposed to be a standard and always follow your number, not your phone. When you cancel cable TV you aren't expected to cancel your premium channels first.