A cheesemaker I know got his product, after long negotiation and lots of work, in to a major UK supermarket whose name sounds a bit like Bainsbury. After a few months the supermarket came to him and said they were going to do a BOGOF deal on his cheese, and he had to supply the free one.
Now you could try to argue that cheese has a 'season' and so this small scale artisan cheesemaker had it coming because he had lots of cheese that needed shifting and the huge supermarket was just doing him a favour. Or you could accept that the supermarket is the worst thing to happen to food producers in five decades and stop defending their bullying of food producers.
The outcome of the tale was that the cheesemaker told the supermarket to go and fuck themselves. But the only reason he was able to do this was that he was selling his cheese direct to the customer through farmers' markets, and selling through small delis and the like who weren't trying to fleece him to sustain their corporate profit margin. If he had been entirely reliant on the supermarket for his sales he'd have had to suck it up.