to get it back you cant
Yes, talk to Diango in Draynor village to get back any lost holiday items.
noob you buy it
i go jagex ltd
Go back to the start, and try again.
Yes. You just simply go back to where you found the shield and get it.
There is no way to cheat on Runescape, may people have tried and lost runescape accounts over it.
You don't need it anymore, once used once, you won't need again.
If it is the shield that your gang had you can simply go back and get it. But if it was the other gangs shield you need to get someone to get you it.
read link below
If you look-up a quest guide for the quest your doing, assuming it is a quest, look for a Q & A section it should explain a good answer.