good luck with all of the above. two years ago, housing benefit said we owed them over �1200 from 7 years previously. we tried to query it and appeal it, but were told (by their lawyers and statutory processes etc.) that the timeframe for appeal the decision had lapsed (it is 6 months), but we were only made aware 7 years after the fact and never got any sort of explaination from them either. we only paid up after they started court proceedings and they wanted the whole lot in one go, too. in answer to your question, yes they can ask for it back, no there probably isn't anything you can do about it and you'll be lucky to not pay it in a lump sum. the govt. agencies are bas****s when you owe them money, but when its the other way round, they don't want to know!