It looks  like it is the same argument starting again. 

I do not say it is a timber sign and I do not say it is made from  oak, pine etc. I say it is wooden because it is made of a wooden material. If MDF is a craft wood everything that is made of it is wooden.

There are  billions of products made of MDF(signs, toys, furniture, picture frames, doors, mouldings and much much more) they are all called wooden(wooden signs, wooden doors, wooden toys, wooden picture frames, wooden furniture etc). MDF is not only a craft wood, it is a common wooden material used everywhere for indoor application. Why on earth  one person out of sudden has got  a right to decide that it is not a wooden material anymore and now nobody(starting with me) is allowed to call products made from MDF  wooden products?

Re your comment about "keep the sign and give a full refund". If you want to support your advise financially I will from now give a refund to every unhappy customer no matter why they are unhappy and let them keep their items. Then I will contact you and you will come with food for my two kids to feed them. How does it sound in regards for your proposal for me to work for free and even to loose money on postage to every unhappy customer? 

Isn't that bad enough that paypal does not care that Australia Post looses packages and sellers are the ones who pay for it in full? Let's add more to it to keep all customers happy. 

P.S. If you had read what I said earlier you should have noticed that I offered her a refund instead of a store credit. She refused to take it and told me that she wants to keep it.