I work in one and someone brought their sausage and egg mcmuffin back because it had a tiny bit of egg shell in it
Which should not have happened (a newbie that didnt think to check before they where cooked)
But she'd eaten around it and brought back the smallest bit of shell on her finger and screamed for a refund
Another is a couple that come in
They had a 'vibe' about them (which I cant explain but if they where found to have been killing newborn babies and drinking their blood,it would not surprise me)
I hated serving them-they really made me feel frightened for my safety
Every single time something would be missing from their order-but they'd only notice 10/15 minutes after they got their food
I would triple check their order before handing it over and everytime they would complain
The manager had no backbone at all and would replace it while giving me a bollocking and threatened me with the sack more than once
Anyway,she left and we had a new manager start and she took no shit from anyone
I explained what had been happening and she sat at the cctv,watching them
They got the food,would eat most of their order,hide the wrapping in their coat/bag and complain that that item was missing (of course it was,they'd scoffed it!)
They got a shock when she came barrelling round the counter and told them their scam was over-she knew what they had been doing and had proof
They hit the roof-screaming and shouting at her and threatening me
They complained to head office but they ended up siding with us and I've not seen them since
So I was complained about for catching them in their scam!