on the walmart receipt it says not to worry if you lose your receipt,we can look it up buy the numbers on the battery,but when they looked up mine it was not even in the system so they would not exchange it.i went home and found the receipt and went back,they tried looking it up again and said im sorry there is nothing in the system that shows you even bought it.then i whipped out my receipt and showed it to them and i said is it in the system now.they gave me a new one and the price had changed and they gave me 21 dollars too. why was my battery purchase not in the system