eBay

I’ve just sold a item but she was bidding on behalf of friend it sold then she asked me to sell to under bidder eBay said type in search bar they caddy but nothings coming up please help

I used eBay through my phone & recently I sold two items to same customers all sold everything's completed goto delete items do that then they reappear but checked on a computer but not showing,tried deleting app & reinsuling but still showing, pleas...