in my hungover state ive wrote 12/5 instead of 12/1 on a slip, and the bird behind the counter has put it through, its for the national and its obviously wrong, will they pay me out if its a winner at 12/1?
Just kidding yes they will, best go there and tell them it was 12/1 and have the odds on the slip changed in case it wins so they can't give you less as odds are always changing.