How to retrieve account that has been hacked and email/password has been changed

My first account that I had created 6 years ago has been hacked and the email and password to the account has been changed and I cant seen to retrieve it at all. It was a premium account and I had spent a lot of time and effort in that account grinding the gears and achievements for my characters in cata, wotlk and mop. I have recently created a new account to play wotlk again but my old id was premium and i had 3 toons that were high gs almost BIS and I dont want to lose that account. You guys must be wondering why not just donate again but I cant donate from my country(Nepal) as international payment is not an options here and I had my friend donate it for me from other country so that i can skip the queue time and play wotlk without wasting time in queue. I had lost the ID like 3 years ago firstly and just recently got it back like few weeks ago after warmane changed my email but now the one who hacked it and used it is changing the email again and are not letting me access it. And now I have sent 3 mails to [email protected] but they have not sent back any reply to me as its been a week or so. When I had my ID back i looked around in my account history to find a ticket that said that my id was bought by some other guy from someone and it even had in game character names in it to whom the player had gifted coins. The account details also had IP addresses of the account buyer/hacker which I wanted the warmane devs to ban if possible but I still have got no reply from them. I still have proofs that I was the original creator and I am the original user of that account which I have of course sent to the main to warmane but I still have got no reply, even the previous replies were super late like months later or something. I dont know how my ID got in this situation but its depressing and painful to see that all those hours and hard-work, the sleepless nights spent to make the characters from level 1 to what they are now (had like 4k achvs+6.3k both balance and resto dudu gear+5.8k feral/tank gear in main toon in wotlk and many more in cata and other toons) and I would love nothing more to retrieve it back and play my character again after 5 years. I wanted to leave a legacy to my children and tell them a story about the great character Axhillex(which has now been changed to Ironhound by the hacker or account buyer) but now there is nothing left of it which is really sad and depressing to me. So, please help me out guys cause I love this wow community and I dont want to let go of it because of this reason out of many.