Health risk/ Expired stock/ Horrible customer service

I bought 5Kg of flour at Foresthill Checker hyper through Sixty-60 and only to find out that the flour has expired and worse part it has worms inside. I went back to the store to return the flour because closes at 19:00 but when i got to the store at 18:50, already the store had closed so clearly the trading hours written outside the store are not adhered to, i then decided to go to another Checker near-by at Mall@55 because they close at 20:00 but also when i got there i was told stories after stories eventually i asked for their Regional Manager's contact numbers because what i was getting was horrible customer service, to think that they are putting our health at risk by selling expired stock and with worms but i was struggling to get the flour exchanged.

Foresthill Checkers Hyper should just close their doors if this is the kind of service they are offering, i paid a fee for sixty-60 delivery and i must now still drive to the store which cost petrol. I don't see myself ever shopping at Checkers (all checkers).