jquery .click() event.preventDefault() not working

Since your links are appended dynamically to the page, you need to use document.on() to capture the click events.

the syntax for appending event listeners to dynamic content is as follows

$(document).on( event, selector, callback );

so your click handler would become:

$(document).on('click','.filelink',function(e){

 e.preventDefault();

 //code here

 return false;

});