Mekach Taus-The Torah’s Return policy on spoiled food products:
The Torah law: [The following law applies in all areas which do not have consumer laws on this issue:] One who purchased a food product and discovered that it was spoiled at the time of purchase, is entitled to receive a full cash refund for the product from the seller. This applies even if the seller is a merchant who himself purchased the product from the manufacturer, nevertheless, he is liable to personally refund the purchase from the buyer. [Thus, the seller cannot tell the buyer to speak to the company manufacturer for a return.] This applies even if the store has a policy of no return policy on foods, fruits or vegetables, and the buyer was made aware of this at the time of purchase. This however only applies if the food was already spoiled at the time of purchase. In a case where one is unsure, the burden of proof is on the one desiring the payment, which in a regular situation, is the consumer. [In all cases that the seller is liable to accept a return, he must refund the buyer with money, and not with store credit, unless the seller does not have any money to give.]
The State law: The above Halacha is only in effect in an area that does not contain any consumer laws regarding the issue of returns on spoiled food products. If, however, the State in which the purchase took place, contains consumer laws and policies which are accepted upon that area, then the laws of returning a product follow all those laws and regulations for all purposes, unless explicitly stated otherwise by the buyer to the seller at the time of purchase. [Thus, if a certain State has a policy of no returns on food products, even if found to be spoiled from the time of purchase, then this policy overrides the Halacha, and the seller does not have to reimburse the buyer. Likewise, if the State law permits the seller to reimburse the buyer with store credit, then he may choose to do so.]
The store policy: As stated above, a store return policy that is not legally protected by State law, is not binding on the consumer, and he reserves the right to return a food product that was spoiled from the time of purchase and receive reimbursement.
In all areas absent of consumer law and regulations regarding the return of spoiled food products, the buyer has the Halachic right to demand a cash refund for his food product, from the store, if it was spoiled at the time of purchase. If the buyer already paid for the product, the burden of proof of when the food spoiled falls on him. The personal policy of the store does not carry any legal Halachic weight in this regard. In areas with consumer policy laws regarding return of food products, all the laws are Halachically binding on the buyer and seller.
 Michaber C.M. 232/3 regarding general law; 230/7 regarding spoiled beer; 232/16 regarding spoiled cheese; 232/19 regarding bloody eggs
 Rama 232/18; Tur in name of Rosh; Aruch Hashulchan 232/30
Other opinions: Some Poskim rule the merchant may send the buyer to the original manufacturer for a refund. [Michaber 232/18] According to this ruling, all food chain stores may tell the buyer to speak to the food company for a return.
 Michaber 232/7; Aruch Hashulchan 232/11
 See Michaber 232/11; Aruch Hashulchan 232/17
 Michaber ibid; Aruch Hashulchan ibid
 Aruch Hashulchan 232/37
 Michaber 232/6 that we follow the Minhag Hamedina regarding the definition of a Mum, and Michaber 232/19 that the Minhag is not to accept returns on eggs, and Minhag Mivatel Halacha! See Aruch Hashulchan 232/7 and 30