Because items are not resellable once opened, especially food items. Would you buy a restocked previously opened item? I suspect your answer would be no. The store owners know this and would have to mark it as a merchandise loss. Large supermarkets have a budgetary leeway for a loss of merchandise, but small business owners do not. Try to find a smaller size of the item in question, in case you don't like it.
Because that's not hygenic and not resellable. Also, small market like this won't have all supports from the vendors.
Small grocers usually don't allow you to return food items because safety regulations require that the store throw away the food. While a big grocery chain may have the profit margins to allow open container returns, very few small grocery stores can afford to take the hit. This of course does not apply to food that has spoiled or otherwise gone bad, which you should be able to return (within a reasonable amount of time after purchasing). Before buying items you aren't familiar with, check online for reviews or ask friends/shopkeepers for recommendations or thoughts on a product. Some items come in different sizes, so always opt for the smallest when trying something for the first time.
ask them but small markets like this are strict
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