Well, my experience seems to be different from 
everyone else's.  I've won five different 
auctions on Mandarake JP and only once (the first 
time) did they send me an email.  I bid very 
oddball amounts, so I am quite certain of when I 
have won, but no email ever showed up.  Each time 
I had to politely email them and ask them if I 
won the cel, and they would reply that I had 
indeed won and that they had emailed me but never 
heard back.  Very troublesome, and it has 
certainly discouraged from bidding more often.

Anyway, if you're *quite sure* that's your bid, 
then maybe you should write to them and politely 
ask (even though it clearly states on the 
Mandarake site that you shouldn't do this).

And when bidding in the future, always try to bid 
a recognizably unique amount, such as 4384 rather 
than 4300 or 4444, etc.