Facebook page and group scam?

Hello! I bought a page linked to a group 1.5 months ago. I became the admin of the page and group with my personal account. However, I had another admin on the group (the page itself).

Yesterday, in the middle of the night, the page did changes on the group without my consent, removing me and the page itself, and put a fake administrator in the group. Also the page was unlinked from the group. Now, it's clearly I did not make this changes, I suppose the owner (which is a company) still had acces to the page and through the page to the group. Is this possible? I lost a group of 47k members, but somehow I am still the admin of the page.
Can someone explained what happened and how?