bad pies

On saturday 04 august i went to the scottburgh woolies and purchased their pies that they had on special - 2 for R100. I bought 4 pies amounting to R200 - 2 chicken and 2 beef pies. I took the pie out from the freezer and let it defrost. i put it in the oven for dinner last night as per the instructions on the box. when i tasted it it had a funny after taste. i mentioned to my husband and he said maybe its off. i retrieved the box from the bin and saw the sell by date was the 03 august and the use before date was the 04 august. how is it possible that the use before date was the same date i had purchased it. how is woolies keeping stock like this on their shelves. i was violently ill last night and am very disappointed in this. we ended up not having dinner last night as i would not give this to my kids. woolies are supposed to sell foods of quality as we spend a fortune at your stores for good food. really unacceptable