Nokia 5610
Wallpaper and ringtone which i am setting is getting changed by itself

Dear Sir,

I am having a nokia 5601... i took it on 11 feb.. its still in guarenty period... Its not even one yr n i am encountering several problems..

Prob 1 : For some pupose i removed the memory card.. when again i inserted it.. it was asking pasword which i never set... i gave it for repair... all my data got lost including images, sms, contacts etc...

Prob 2: After this, it turn up with more problems, wallpaper and ringtone which i am setting is getting changed by itself..

Prob 3 :Timing of sms's is not showing properly...

Kindly suggest me the remedy.. what should I do... I expect an immediate respond from such a trusted company..

Thanking You...

A.K.Singh