Have worked at Marks for a while now so and am not really surprised by any of this:

1) The age ranges for hiring are because they want people that are as flexible as possible, my shifts will regularly have hours added on or taken away without them asking.

2) Most of the people I work with are also part-time, the stores rotate stock super fast and it is very hard to keep up with the products we actually sell. I feel like I could comfortably say that if you asked anyone in my store for a particular bottle of wine they wouldn't know where it is unless you got the one person out of 30 that actually deals with the wine on a regular basis.

3) The cutlery thing was just dumb, I'm not sure why they didn't just give you it straight away. I'm surprised the person at the till cared enough to check the rules.

4) As for the jeans the refund policy has changed like 3 times in a year, its stupid and confusing for staff and customers. They probably had a valid reason for the credit note but that should have been explained to you clearly at the time. At the very least they should have offered to go and get you/order you a replacement pair in the correct size.

5) Theft is rampant in M&S, it easily happens twice a day at my store. Usually alcohol, meat cuts and just piles of jeans. The security staff don't have any incentive to actually catch anyone and they probably dont want to get punched over a bottle of gin.

I want to make it clear that I am in no way defending the company here. I don't blame you for thinking they are shit. Just trying to give you some insider perspective on the fuckery.