Seat bolt has sheared - WTF!!

OK. So I was removing my seat to put some non-slip cover on it. But, 1 of the bolts was cross threaded and wouldn't budge. Had the bike serviced last week (600 mile first service) - I BLAME THEM!!!!!
 
Anyway, the bolt sheared off. Me being me, I tried to drill it out. Anyway, half the bolt is still there, there is no thread left on one side of the hole - slipped with the drill.....The thing looks like a bloody mess - on a brand new bike.
 
Question is, what now needs replacing????? What section of the bike does the seat bolt in to? Can I buy just 1 side of whatever it is?
 
Any advice is much appreciated!!

you might be able to just re-thread it . 

WOW!! The same thing happened to me last weekend when I took the seat off to replace a fuse! I'm assuming it got cross threaded from the inital set up...I only have 215 miles on my bike right now! But seeing that you had the same problem strikes a belief that there may be something going on!!

^Its a consperacy of bad mechanics!

+1 for re-threading.

re-threading would be cheaper then replacing god knows what under that seat, i havent taken a close look at it but my geuss is that it screws into the sub frame. Just be careful when you go to re-thread it and not make it worse. if that doesnt work and there is nothing below it you could try running a nut and bolt that go all the way through or something like.

same thing here, but wasnt just one of them. no no it had to be both of them. noticed this after 600 mile check up when i had to recharge battery "left the lights on" but yea i found that they were both crossthreaded. so guess what? i just let them go in however they want to now and it never goes the same way twice.
 
chace

Same thing happened to my on an R6.  I completely stripped the hole on one side.  I just drilled it out and re-tapped with a larger screw.  It was fine, you really only need one side anyway.

Thanks for all the responses. This sounds like a more common problem than I had originally thought. I've got the bike booked in at the $tealers tomorrow. I'll let you know the outcome......

FIXED!!! And didn't cost me a penny. Went to a Honda dealer about 15 miles away from home, they said that the rear subframe would need to be taken out and sent away to be re-welded - WTF! - £300 or there abouts. Another Honda dealer told me........new subframe needed - £500. Decided to go about 30 miles away to Planet Bikes - Honda dealer in Leicester, who spent 2 hours on it and managed to re-tap a hole, just off centre, put a nice thread in it and use the standard bolt - Fantastic!!!! How much???? They would take a penny. What a fantastic place. I was so pleased, I decided to add 200 more miles on her today!!!!

ha same here.  I just use one bolt.  My came that way and it was 600 miles before i realized it and the dealership are dicks.  O well.