if you're a scammer then gtfo
if you're not a scammer and that jsp user continue to spam in your topics saying lies like "don't trade with him is a scammer" or shit like that
contact a mediator
i had the same problem with Resovia some months ago and i solved it by contacting a medi (check my profile)
/edit: since i can see that your eng skillz are not that huge, i suggest you to contact a Mediator who speaks your language
