How to get rid of a Facebook message in the inbox on iPhone?

I've deleted a thread from my fb inbox on iPhone but everytime i open fb inbox it shows the message even after i have deleted it.

You just slide your finger across the message in the inbox

like ---> … That
hehe!
:)

I had the same problem before but I don't know if my solution works, but its worth trying. Go to facebook and click the top right corner where it shows options. Then it'll show lists of settings and click the account setting. When you reach there look at the left column and click notification settings and… And… I don't know… Or you can go to your phone setting and scroll to the bottom and itll show the list of apps you downloaded. And those are the settings for each app: D sorry this might not help as much as i want it to:/