Default fb app n fb messenger not working

hello I am having a problem reg. fb app n fb messenger.
firstly I am new in this forum so I did not where to post my problem
I use samsung galaxy ace duos gt s6802...running on android 2.3.6
I installed fb app n fb messenger but m nt seeing d phn icon beside my name nor am I getting msg notifications or other notifications in my phn despite having enabled push notification and normal notification in fb n also in fb mssngr..I reported fb but to no avail and sm of my frnds r evn saying dt dey r seeing d wrd 'invite' beside my name and below its written 'facebook' whr it shuld b written 'messenger' whn m sending msgs thru msnngr...I reinstlld these apps 2-3 times n also clrd data..but nothing works..plz help me..n m nt evn finding a soln. onl9..shuld I perform a factory reset?