an old acct went from lv 30 to lv 1.... ummm what?

ya so just like i said in title... i have an old account that i happened to log into today, it went from level 30 to level 1 it seems... the last game registered in my match history is from 2016 where i am level 13.... i am level 1 now on the account... so wtf am i suppose to do here?

edit: all the champ i used to own are all gone... where did they go?