Free Fire Account Hacked in 2021 and Still Not Recovered

I play Free Fire on an Android phone and I log in with my Facebook account. In 2021 my Free Fire account linked to Facebook was hacked. After this incident everything in the account was changed, including the name and the password, and I lost access to it. I had invested diamonds and in‑game items into this account and I can no longer use any of them. I have a screenshot that shows my old Free Fire profile and proves that I owned the account before it was hacked. I contacted both Facebook and Free Fire/Garena support, but I do not understand their replies and my account has still not been recovered. I request your support to identify that I am the real owner of the account, to restore full access to my Free Fire account, and if possible to return my diamonds and items that were on the account before it was hacked.