As Loyce mentioned, Telegram is a scammers paradise but whether you make a deal directly on this forum via PM or off it such as on Telegram, it is a huge risk.
It might be obvious to others but I am unsure until/unless you state it: why did you want to buy a Hero and Legendary account rather than build up your own account as you went along? And did those accounts come with a signature campaign already participated it? $7600 is a lot of money to pay for 2 accounts.
I have mixed feelings about this because nobody deserves to be scammed but at the same time account buying and selling is frowned upon in the forum. I hope you keep us posted because if you have been scammed but have screenshots available then at least we can all tag the associated accounts rendering them almost useless.
At the same time, if you do manage to get access to those accounts and then later they are discovered to be sold then they will most probably be tagged anyway so you really should have tried to build up your own account in your own personality rather try to buy in a risky sale worth $7600.
Recently I bought a Hero and legendary account.
Account price
hero rank : $2400
legendary rank : $5200
Escrow fee: $500
Total amount : $8100
The offer took place in telegram (I already have screenshots of the transaction, involving a trusted third party and the deal went well) after that I login into the account successfully. but after a few hours exactly 6 hours after purchasing the account (hero and legendary) when I tried to login the account didn't work. I contacted them including third parties, I told them I not kidding if they try to trick me because that's why I intentionally wrote in this thread, I'm 99% sure he will read it here.
I gave them 2-3 days to sort this out before the case got long.
one more thing, for the time being I will not publicly provide evidence until they actually return the account I have purchased. but i will if they trick me.