You'll find it's a 1/4" or 6.35mm jack socket, not a 3.5mm. Most music or electronic stores will have cheapie 1/4" sockets for R5-R10. It'll only last a year or so, but is better than nothing. Solder it yourself - learn by doing and over the years you'll save yourself thousands of rand on simple repairs and cables, etc.
Like this:
http://www.fort777.co.za/index.php?main_page=product_info&cPath=269_270_297_315_318&products_id=1607
