Account deleted due to inactivity?

I had created several accounts 5 months ago, one for each classroom in a school. They were definitely opened successfully back then.

Today I noticed that I cannot log in with any of them. The accounts haven’t been used since, except for some testing in the few days after creating them.

Are accounts being closed due to inactivity? Or did I violate some EULA-type rules?

Sorry, we don’t delete accounts from our side. Could you provide more details by contacting me directly via PM?