keyword broad match sucks ?

Hi

I got 2 keywords and bids like this

widget - 15 cent
widget for sale - 70 cent

yahoo recently changed their minimum bids, and the keyword widget got a required 30 cent bid now, so my keyword "widget" stopped working

and then the worst thing happened, all the searches with keyword "widget" got matched to keyword "widget for sale" and in fact i started paying 70 cent for the keyword "widget" .. and the keyword "widget" itself is a junk keyword for me, which doesn't convert almost

I see lot of these in my server logs:
Refferer - http://search.yahoo.com/search?ei=UTF-8&fr=yfp-t-501-s&p=widget&rs=0&fr2=rs-top
Request URI - /?OVRAW=widget&OVKEY=widget%20for%20sale&OVMTC=advanced&OVADID=xxxxxxx&OVKWID=xxxxxxxxx

So , in fact yahoo started charging top money for a junk keyword by simply matching the junk keyword with a top performing keyword ..

1. can i get my money back from yahoo ?
2. how do i prevent this from happening in future ?

Thanks

 

I no longer use advanced match on Yahoo - it's standard (exact) match or nothing!

Adwords, selects your exact match over Broad or Phrase match when possible, yet Yahoo doesn't do this. So I decided to just stick to exact match.

 

Dont use broad match, they may send junk traffic....just disable and see you will get decent traffic.

 

if you use advanced match, you need to use excluded keywords with it to cut off low quality traffic.