I cannot speak to the exact law in your jurisdiction. If this were in Ontario, the practical answer is that you should ignore such a request. I would surmise this was a demand that was sent as a result of a shoplifting incident. While in Ontario store owners might have a technical claim to nominal damages, as a practical matter these claims are not pursued. It appears to be however a lucrative business for stores to send out these demand letters or retain agents with whom they have a sharing arrangement to do so. If one person in 10 responds, they are ahead of the game. See the original response to this kind of demand:

www.golishlaw.com/answers/991cmmt.htm