without just deleting the item and recreating, that is actually flooding your database. web owners have an option on removing it from the shop by accessing phpmyadmin panel. go into your database where all information is stored and find the tab called shopitems. at this time, you will find the shop ID, and item ID. you will find the same item in the same shop 2 times so just click on the X and it will be gone out of there. this would also not give you internal errors.
by doing the way you are now, you will create an over load in the server and cause a 503 internal error. it's not that bad but it can lock you out of the server till the server does a restart or just buffers a little bit more so it is back online.
if you want someone to code it, I can code it for you but for a price.
