You don't need your till receipt if you paid via a card as your statement will be enough proof. If it is an Aldi product then you won't even need that, providing it isn't something well and truly no longer sold and years ago. They had no right whatsoever, under EU law, to give you less than the purchase price if it was obviously one of their own products. There is now a SIX year period during which you can return a faulty product. Most store employees do not understand this law regarding faulty products. Also, shame upon them, neither do most stores. Morrisons do though. It is in the interest of everyone to look the EU gtee laws up. You will be surprised. Once again typical of this company.