NC for this.
I moved out of a rented house recently. In the course of cleaning it and making it nice, I used a product which made it look worse (being deliberately vague so as not to be outing). I complained to the manufacturer and said that because of their product I might lose my security deposit. I asked the company to pay to have it put right. There was a lot of emailing and a lot of stress (for me). They didn't tell me that they would put it right, instead they asked to deal directly with the landlord, so I put them in touch.
Next thing I know, I receive a cheque from the company for several hundred pounds. It came with a letter that said something along the lines of 'we hope this restores your faith in our company'. The letter said nothing about what the cheque was for - specifically, it did not say anything like, 'this money is to pay for the damage to be put right'.
I paid the cheque into my account. A few weeks later, the company contacted me to say that they sent me the cheque by mistake, and that they meant to pay a contractor that they had booked to do the work. They want me to repay the money.
My view is that they have basically given me a gift and then changed their mind about it, so have no right to demand it back. There was nothing in their communication that could have led me to think this was a mistake - their letter was, basically, 'Hi Hamster, following your complaint, here's some money to make it right'.
Can anyone advise about the law here?