Taken from trinityrooms.ie
I want to buy an item in the sales but there are signs in the shop that claim “Sale goods will not be exchanged” and “Goods on sale cannot be tried on”. Can the retailers do this?
The consumer’s right when buying in the sales are the same as at any other time. Your legal right is to a replacement or refund in the case of a defective item, therefore it is an offence for retailers to display notices which say “No cash refunds”, “Credit notes only” or “Sale goods not exchanged”.
Such signs cannot affect your statutory rights.
Unfortunately there is no obligation on the retailer to take back goods that are not defective. Many retailers will still exchange an item once you have a receipt but they don’t have to. Likewise, retailers are not required to provide facilities for trying on clothes. However, where possible insist in order to detect any possible defects.