Hi there
All card transactions have a 180 day "charge back" time. This means that any transaction can still be returned with a legal (ie fraud) claim being lodged within 180 days from processing such. Debit orders however have a 40 day "return time".
What this basically means is that if a dispute is lodged within the time frame - the transaction can still be returned - even after a longer period of time; but you have to make the bank/merchant aware of the legal 'dispute' within the time frame.