I have a very real concern that I am going to end up as one of those people who spends all their time writing off letters of complaint or "I thought you would like to know..." to big companies. The problem is, they keep incentivising me with free stuff.
A few months ago I bought a bottle of Coldpress juice from the supermarket. This is usually delicious, but that bottle was awful - it tasted really earthy and off. So I returned it to the supermarket and got a refund. A few weeks later we received a replacement bottle of juice through the post with a nice letter. Great.
Then just after Christmas, Zachary noticed that on a certain box of own brand cereal from a well-known supermarket there was a recipe for some kind of crispy, marshmallowy snack bar using the cereal. The first instruction told you to 'melt the marshmallows' but Zachary noticed that the ingredients list didn't contain marshmallows! Normally I would totally ignore this, but after my result with the juice, I wrote a letter to said supermarket and this morning a letter from them arrived. It contained a £5 giftcard to use in store. Brilliant - bring on the complaining!!!