Last Thursday morning I sent my nearly 5yr old dd to get her school shoes on. After about 5mins she hadn't come back and shouted that she couldn't find them. I went to have a look and couldn't see them where all the shoes are kept either. So she put a pair of boots on and went to school. I thought I must have left them at gymnastics the night before and said this to her. Stupid me. Told dd we would go and buy a new pair on Saturday if they hadn't turned up by then. £36 later in Clarks we now have new school shoes (in the same size as her old ones!) She puts them on this morning and says they feel funny I want my old ones. Explain new shoes do feel funny at first etc and anyway she has no choice. She then disappears and comes back with her old shoes which she had hidden behind a cupboard under the stairs 
Part of me wanted to smile at the ta-da flourish she presented them with but actually I'm quite cross I spent an unnecessary £36. There is nothing wrong with her old shoes. I can't take back new shoes as have treated and named them. What would be a suitable punishment do you think? Small,silly things result in the loss of a marble but I kind of want this to be a little more serious as she not only hid them, she lied, allowed me to repeatedly say silly mummy left them at gym and then produced them when she decided she'd rather not wear new ones. She is generally a lovely girl but little fibs are starting to creep in. we had a quick chat this morning and she knows I am cross and that there will be a consequence. She doesn't know why she did it.
Apologies for lack of paragraphs. iPhone app won't let me go back and edit.
Sorry for lack of para