Thought I’d share my experience cancelling visa and WP. I had to cancel the visa before the WP - this was no problem as I had the proper papers from employer, and I extended for 7days to leave the country. After this I went straight to labour department and after waiting for 2 hours I was told that I cannot cancel my WP myself, even with all the proper papers. The employer has to do it themselves. Hope this will help other people and save you some time (and money in taxi fares).