Go into Options (ESC key, or click on the wizard book in the lower-right corner). Now choose the second tab from the left and set "Smoothing" to "Crowns Shop".
If that doesn't work, send in a ticket to Support.
Most of the items in the crowns shop and any items from vendors that say 'crowns only' in their description can't be bought with gold. if this doesn't explain your issue, give more details on what's happening when you try to purchase the items you want and can't buy. anyway, good luck in klaptopia.
