Need help asap

Hi I don’t usually post things on the internet but would like some advice, I sold my old school runescape account to “Accountwarehouse” and it was all going fine, they paid the money into my paypal and I thought that was the end. I received an email today claiming that I have recovered the account and that then will take it further as it is “fraud”. I don’t even own a computer anymore let alone have time to play games. Which is why I sold the account in the first place, I have emailed them saying that it was not me and what I should do, but they’re threatening to take it further and not listening that it was NOT me who recovered it. I suffer with bad anxiety and this is just too much for me at the moment. I genunnly have not recalled the account as they have claimed. I’m just looking for help, any suggestions would be appreciated. Thank you so much