Until a few months back I was doing a charity fundraising job (you know, bucket, high street/inside supermarket doors, "give me money I NEED"

and every £25 raised £10 you kept.
It was disgusting. I used raise £150 daily (but 'enthusiastic' (read

retty girls) could easily raise £180-200 pitching 9.30 - 5.30), at the end of the day your bucket would be opened by the staff and your pay would come DIRECTLY from the bucket.
I couldn't live with myself I was practically begging for money, but it was so much more interesting than self stacking and the competition to take home more money was intense, i.e., a list of 5 best fundraisers for the day, these fundraisers got to go to the best locations the following day etc.
I had to chuck the job in though after I almost got arrested for pitching in a tube station which is illegal, and besides all the showers in the world couldn't make me clean (and i'm not talking about how I smelt from being next to benefit-fraud stinking chavs/ criminals who couldn't find real jobs).
But anyway, the best way to get rid of charity fundraisers isn't telling them to "fuck off" you either a) upset a pretty girl b) get punched by criminals - i've seen both. You have to sympathise, telling them how hard it must be to stand around all day/confident to approach people/good cause etc basically act as though you think they're volunteering for free - then swiftly move on.