Fortnite Account sold on ebay now he threatens me with ad?

So, I sold my fortnite account on ebay about 2 months ago. The buyer got the data and changed the email. This was also confirmed etc. He told me that he will resell the account. Now he says that he has no access to the account and accuses me, even though I have no access to the account. I personally think he has resold the account and now just wants to have his money back.

What do you think I should do now?

Can these accounts be sold at all? No, you only have the rights of use. The account was most likely blocked by support. They noticed something. You will have to refund him the money

You're both to blame it as much as you are

it is forbidden to act on accounts account was locked and rightly you will be threatened I would tell him but so and say that he likes to do it but he would blame just the same

The account was locked with security by the provider, because it is forbidden to sell accounts and also to buy, most networks have to stand in their terms and conditions. If you catch it will be blocked, and with high probability you can't get the new Acc.

Ergo both fault. There's nothing to show here.