Re: Ha!
This exact thing happened to a client of mine! Somehow their domain became registered with Microsoft with an Office365 tenancy. It was a 2 week nightmare to fix it and Microsoft could not tell me how it happened. They kept forwarding me around support departments because "you don't have an Office365 subscription" and then "this is an Office365 support issue". I don't recall what the final solution was, but it happened after I told them "You have somehow hijacked my client's domain and claimed to host their services. This can't be legal, can it?"