Can you cancel your auction?

You can not remove things from the shop for free. There is a tax on it to prevent players from using the shop as a storage system. So in your case removing your items will cost you 240g, since there is a 15% sales tax.

 

You can cancel your auction but only by buying it from yourself.
You would pay yourself and then receive your own money back, but the tax would take off a percentage of your gold spent.

I know the shop was bugging a bit for me yesterday, so be more careful next time then.

 

To sum it up:
You can not cancel offers in shop. The only possibility to get the items back is buying them. To buy them you would need enough money and you wouldn also loose 15% of the money you spent for the purchase. The tax is there to prevent the shop from being used as a storage, whee you would sell your items highly overpriced and buy them back when you need them.
You should always be careful when you sell something and make sure you put all numbers right
(I can already tell mossy cobblestone gets sold rarely for any price doe)

Question answered, locked.