Decode email symbol from '%40' back to '@'

hi, good day, i am using wp for my website, i have an issue, i think it is the browser or some plugin encoding to ASCII character-set and caused the issue. when user register using fb, because fb will use their email address to register on my website,but their email '@' symbol becomes/encoded to '%40' in ASCII show on browser when output to visitors, thus other users/visitors try to click to see their profile and it link to an error page did not found because i guess it did not match the request url in database. (i think this is for security to prevent email address to be grabbed by email spider). this only happen to facebook-registered user which use email as user ID or login, others social login so far no have such problem(not yet try intragram). you may take a look at my site: go to one of user--> [login to view URL] then scrowdown to taggle 'Semak Poin yang tertinggi terkini', you will see 'Top10SukaPoin:' then click on either #5 Xissy Leex or #8 Hbwsl Hbwsl (those user are use fb to registered) you will link to error page 404 let me know whether you can fix or decode it or not and pls bid only if you ensure you can do it? below is some info i found online about this issue for your reference: how to decode email: [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] regards Lee