The prime option has not been active for a long time, think it was taken away as an upgrade a couple years ago even, so I'd assume that the plan expired on you since it was paid for 3 months at a time if I recall right, with the migrations any remnants of old, no longer in use, plans are removed.
In this case however it was a manual purge of all accounts that had not had any login activity for the past 60 days, the requirement for free hosting is once every 30 days.
Due to the nature of how the purge was done, I have now restored your account.
In the future you would need to either login once every 30 days or upgrade to premium hosting which does not have any login requirements.
