I don't use AIO's (well, strictly speaking i just got my first through) so can't speak from experince but did you buy them new? If so when? They are guarunteed, i thought it was 6 months but someone said on here that it's been increased to 12 just recently
Oh, hmm contact the person you bought it from and see where they got it from and how long ago. If they are nice they may contact who they got it from if they bought it in the last 6 months (which is likely, they seem to go within 4-6 weeks of new) and you may get a new one.
It seems to most often be the peppermint that goes.
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