Pull chord detached from ceiling rose?

I pulled the chord to switch on the main centre ceiling light in the bathroom as usual. However, when the light came on I was left with the pull chord in my hand. It had separated from the "ceiling attachment". Two very light white pieces of chord join to make one chord lower down .How can I attach them again so that light switch works. Had to remove bulb to "switch off" the light.

Máire
April 2009